Update: Got my 2.8A back, and it's back from the dead!!
Apparently their 'top technician' said it was a write-off, but after some discussion Dimitri (the owner?) took it upon himself to have a tinker himself. The shutter's working fine except that two speeds are prone to jamming (1 sec and 1/5 sec) -- which I can live with. He mentioned that the complete set of Rolleinar 1 lenses with perspective correction that I have for this camera is apparently worth a zillion dollars. So there.
I have written 'writeoff my ass' on the back of the camera, and 'beaterflex' on the side. It's never going to be pretty, but that was never the point.
I haven't developed anything out of the camera yet, but it feels OK so far; the Rodinal will tell...