Nanjing automotive are going to produce the 75 in china and are apparently going to resume some kind of production at Longbridge so all the dealers (obviously a lot of them have shut down since what happened), will most likely supply Nanjing built 75's etc in the future. God knows when this will be, and will the actually start any kind of production back at Longbridge? I doubt it.
Regarding parts, the distribution is performed by X-part, a company owned by Catapillar so I wouldnt see parts supply being a problem from what I have read. Engine-wise its the BM engine so shouldnt be a prob with parts for that either.
An interesting place to wander over to is
http://www.austin-rover.co.uk/ Im sure you guys will be able to remenisce (sp?) about the lovely old marina's and Allegro's you've owned in years gone by..

Also tells a lot about the recent demise.