That is a shame 971 has experienced another failure.
There are other steamers in Qld, but the politics of acquiring them is complex. Without begrudging MVHR, the sale of 967 is an example.
Speaking of which, Seeney is advocating rail trail grants, including to MVHR, with the obvious connotations:http://m.gympietimes.com.au/news/Mary-bikeway-plan-comes-out-of-rail-grant-invitati/2330225/
The most ideal motive power solution might be the acquisition of a diesel locomotive. Problem is Aurizon are always shipping them offshore lest a third party operator get their hands on them, but there seems little threat of sdsr usurping aurizon dominance on the Southern Downs. Even if any remaining branch lines are deemed fit for traffic, the below rail access charges make road freight a nobrainer, even if motive power was available. Plus there's the lack of paths down the range for Brisbane-bound trains.
Perhaps SDSR could aim for a heritage diesel? Or a railmotor? Theres always a few of those around, derelict, but the owners will not part with them. Retention toilets aside, once the initial mechanicals are made sound there's little to do to keep as a backup.
Excuse my ignorance - what happened in 1947?