I used a decorators scrapers like these:
https://www.screwfix.com/p/no-nonsense-decorators-knives-3-piece-set/20018 to remove the side rails. Came away lovely and no damage to rails or decals (which were removed anyway). Make sure you remove the holding bolts at the front first.
Powder coating is def way to go. £20-£40 should cover blasting and coating. Recommend you get the legs done to match.
Not sure if all Williams pins are chromed - I think mainly Williams machines with Stainless Steel side rails, lockdown bars and legs. Metal bashers tend to prefer to keep stainless natural and not powder coat it.
Dents and scratches can be fixed - could try a local metal polisher.
Good luck