Our member Gwiwer may have more accurate background and information...
My attention has been drawn to this thread.
W-class trams first entered service in Melbourne in 1923 when car 219 was delivered. Since then and until car 1040 arrived in 1956 some 756 cars were delivered with traction and body styles varying considerably between manufacturers and as technology progressed. The number sequence includes rebuilds, a few other classes (the X and Y classes) and a small batch which was never built so does not tally with the actual total of cars constructed.
Most of the early ones were built as or were converted to class W2; many of the later ones were built as or converted to classes W5, W6 and W7. Some are or were prefixed S (so class SW6) meaning they had, or had been converted to, sliding doors when open sides was the class standard. All cars remaining in service have had sliding doors for many years now.
Of those which remain in service with Yarra Trams (nominally 53 though several are withdrawn or stored and unlikely to return to service) most are from the latter two classes with just a few slightly earlier W5 types.
As newer trams were introduced staring with the Z1 class in 1975 the oldest of the W-classes (by then largely W2 types) were steadily withdrawn and at that time were simply burnt with the frames sometimes cut up for salvage, or were sold privately to museums and private buyers. Some went on to be chook sheds, home extensions and other similar uses and some of these survive today. One W2 was purchased by Sir Elton John and was shipped to his home in Windsor, UK, but is not available for public viewing.
Continued delivery of newer trams along with service cuts saw great inroads being made into what Melburnians regarded as their iconic tram fleet. Representations were duly made and all remaining W-class trams were classified by the National Trust as heritage items which could neither be disposed of nor removed from Victoria. That classification remains in force.
This resulted in huge numbers of redundant trams being stored with no further use on the streets and no lawful way to dispose of them. Some were placed in storage in Preston Workshops while a large number (approximately 200) were accumulated in a redundant factory premises in North Melbourne. It is those cars which subsequently moved to Newport East Block where many remain.
Access to East Block is extremely restricted for good reasons. There are structural issues with the vehicles inside and possibly the building itself making it a hazardous place. Also stored in there are items of rolling stock involved in serious incidents which are awaiting the outcome of legal proceedings before scrapping or repair is permitted. As such they are sub judice
and may not be tampered with in any way nor may images be taken of them without specific authority.
Word from those sources granted access to East Block over the years is that around 150 trams remain; the actual number reported varies slightly from time to time as some are finally broken up (mostly for spares or restoration projects), some more are moved in (including most of those which were once stored at the workshops and in the old Thornbury shed opposite) and a very few are moved out to new homes.
Those which are present are mostly reported to be in an advanced state of bodily decay and potentially unable to move under their own power again. They have been stored for some 35 years during which time most of Melbourne's tramway has been modernised making it impossible to run such elderly vehicles without very extensive rebuilding. Given that YT intends to cease operation of its remaining W-class trams other than the dozen or so required for the City Circle there is no need to rebuild cars which are up to 70 years old.
Most of those stored are from classes W5 and W6. As noted above the earlier types (including the very small number of W3 and W4 cars built) were largely disposed of before the listing was applied.
They may not be sold, moved out of the State nor otherwise disposed of except under very strictly controlled conditions. One (965) was cosmetically restored and sent to Denmark as a wedding gift from the State of Victoria and is now owned by Crown Prince Frederik and Princess Mary. That is a unique exception.
No future has been determined for the remaining cars. The existing museums have probably more than they need. Occasional murmurs arise of a new working museum project being set up in Melbourne but given the potential cost and lack of a suitable site such hopes are likely to never become reality. So they continue to slowly decay for no better reason than their continued classification. If that classification were removed it might become possible to purchase one but not until then.
W-class trams from the earliest to latest types are quite well represented in preservation already. Some are in working order and operate at locations such as St. Kilda (SA) museum and the Sydney museum in Loftus. At least one runs on a demonstration line in Auckland NZ at the MoTaT museum while others as far away as the USA are still in operation though sometimes heavily modified. Some earlier W5-7 withdrawals escaped the classification and have travelled far and wide. In Melbourne they are in service on routes 30 and 78 (generally restricted to weekday daytimes) and route 35 City Circle and heritage cars may be seen at Hawthorn depot museum.
Even if it were possible to buy one now the chances of transporting one from Newport to another location without it simply falling apart might be a debatable consideration. Then there is the very significant cost of restoration. When even the museums struggle to fund the works a private individual is unlikely to do better without considerable private assets and skill.
The best source of up-to-date information on the entire class is Vicsig at http://www.vicsig.net/index.php?page=trams
While many hard-copy publications also exist many are long out of date notably the standard reference work "Destination City" which has not been republished since 1993.