Recall a kid using his stolen mopeds rear driven wheel against a roundabout with his mate on the latter going round at a fast pace... as one may guess, it did not end well.
That explains a lot!!!
Valves nice an free... and will stay closed more of the time now... dogs, sheep and horse have all fled the area on start up!
Sadly no 'quiet start' mode to keep the sleepy hollow placated.
Given the age of your battery, I would recommend replacing that first.
Also, remove the old one for 24 hours to ensure any remedial current has dissipated.
Good luck.
Silver can be a bugger to match, and rust is a real devil to sort permanently.
If it was my money, unless it's your perfect spec, I would look elsewhere.