This is the place for threadles, check the Victorian Sweatshop forum too; there are some very clever guys sorting out treadle irons, identifying model number, missing parts, etc. There are ways to improve upon chiped and flaking shellac, if you want it done nearly flawless it's possible, given time and effort; if you allow signs of wear and age you can do a simpler touch up. You need to get the flaking and finish sorted out before you start using the machine, it will prevent further damage to the finish. The decals on the bed looks rather good. The price isn't too bad, but you can probably get far with a DIY effort.
Furniture restores glue back flaky jappaning, fill in gaps and you can hardly see the difference. Check the thread of posts on top of this forum, there's lots of hints on how to improve worn japanning. There are several sources for a new treadle belt, SewClassic, Cindy Peters, ebay,... I think they weld or repair cast iron some how, you just have to find the right guy.