OK. I understand.
Good Brownie Points that you 'turned yourself in' instead of trying to bluff it out.
The green doc you have now is most likely what we call an 'Exit Visa' - valid only to get out of the country, once or multiple. They are usually issued to people without Visas but with Residency but no RUS passport (like me!).They only look at it on exit - on entering they are only interested in my Residency Permit.
Your Exit Visa obviously has a short life. Mine is valid for 3 years when my Permit comes up for renewal.
So, back to the plot -
The Irkutsk boys hopefully have the diagnosis and repairs under control.

If they cannot readily get parts see if you can get them in UK and contact me. Post or DHL is not great as packages invariably get delayed by RUS Customs, so if they can travel in someones baggage to me in Moscow, so much the better - I can get them to Irkutsk quickly and fairly cheaply.
If your remaining hours here allow it, you should spend some time at the local Customs office (hopefully with a biker who speaks fair English if your Russian is as bad as mine!) and get some extention or agreement or permit or procedure understood and to follow - for the bike to remain in RUS for the time being, to be collected when possible at a later date.
Later when the bike moves, we can sort things out about possibly getting it to Moscow or Peter. I have a lock-up garage in Moscow where it could safely remain until you or someone comes for it - if not to get it to UK right now at least get it out of RUS and into EU is probably beneficial. But it could safely live in my garage all winter if need be, assuming its coolant can be easily drained or is -30c!
When back in UK, check your positon with DVLA - they are like circling vultures, waiting for the slightest error so they can impose penalties or Out of Court Settlements - all to shore up their ailing budget caused by their own inefficiency.
Keep me informed of progress - either on this thread or through PM where I will give my Email.
I'll do what I can from here.