OP – if you like the bike then its worth doing the repairs and potentially getting a repaint. If you’re not in love with it you might want to think about something newer.
TBH it sound like the 2 mechanics you’ve dealt with up to now are taking the mickey a wee bit – not unheard of but also not the norm in my experience.
If you’re going to do it all then you might want do the repaint first as you might need some wee finishing touches, threads cleaned etc depending on who you use. Then you can get it rebuilt with new bearings, new drivetrain maybe even new folks all properly installed, greased and lubed.