The original concept for the R cars was 6 x 4 car sets . Two and two seating in both First & Economy classes. Four car fixed consist ACR, BRR, BR, BR . So yes First class and on train catering .
Originally the N cars were conceived as 30 commuter cars for use on the Geelong line. Then along came along a Ballarat by election and the concept became 36 .
Then in 1980/81 Vicrail plan to upgrade country passenger services . N car order increased from 36 to 54 cars in 3 car consists as ACN,BN,BN. (Other parts of that plan Country EMU to run Traralgon, rebuild of DERMS with new motors and generators, re-build 26 B class and 13 T class locos, re-build 39 Harris cars as 13 x 3 car consists. Also 10 new N class locos. Upgrade existing S, Z and E class air con stock . Traralgon DMU and re-build DERMS not proceeded with . Only 10 - 11 B were rebuilt as A, but 10 new N class became 26 . 54 N cars ultimately became 57. 39 H cars ultimately became 55.)
The N cars were originally envisaged as commuter cars only and early delivery sets were ACN,BN,BN . To service the Inter City routes a number of four car S/Z sets were made up of ACZ,BZ,BRS,BS and the N sets were altered progressively to ACN,BRN,BN .
Over time the S cars dissapeared into a fixed Geelong set and eventually withdrawn and now with enthusiast bodies. The BRS cars progressively retired. The AZ & BZ cars progressively morphed into ACZ, BCZ, BZN and BTN . The a/c E cars were progressively withdrawn .
Owing to declining patronage on the old sg SOP VBK and VHK (saloon) and even some compartment cars were put back on bg to handle increased Victorian Intrastate patronage . The 5 x S cars now stored . The saloon cars off sg morphed into ACZ, BCZ, BZN & BTN .