One other thing about converting these to digital - watch for short circuits on the metal bodyshell.

Last night, the TM800 went out of control. I traced the problem to a short between the shell and either:

One of the motor coil connections
One of the motor brushes

Both areas have now had small pieces of insulating tape applied, which seems to have solved the problem. I suspect if the decoder had been one of the 6090x type it would have been fried, rather than just making buzzing noises and apparently being fine after the tape was added.

Great job, Matt.

Thanks all

John - gun blue is a bit hard to get here but I have found something that works as well:

Spray a small quantity of WD40 onto the coupler
Use an old toothbrush to remove the rust
Wipe dry with a paper towel

This seems to leave a very thin film of WD40 which prevents further rust forming, as well as somehow repairing the blackened finish. I'm not sure how it works, but it does! I've not noticed it transferring to hands, other couplers, etc.

Great work,congratulations my friend.You did the best to save a great
classic.