I'm going through an Austin Healey "makeover". The car has been in storage for close to 25-years. The most time consuming part of the "makeover" has been de-rusting and cleaning parts, getting things loose, etc. Bar none, the best technique I came across in dealing with parts is de-rusting using electrolysis. It's amazingly effective, easy as connecting a battery charger to a battery, environmentally friendly (no chemicals) and dead-drop simple. I put a log page on my website. If interested there's images showing just how to set it up -
www.healeymakeover.com. Because it does not involve acids or chemicals there is not degradation of metal should you make the mistake of leaving something behind in the acid bucket. Thick rust comes off almost like paint stripper. Most parts take about 16-hours, but I've had fussy parts that I've just left for several days. In fact, I'm just now leaving to check on a tank we have going that I have had my rear seat pans getting de-rusted. The seat pan has been in for 4-days or so. I have a smaller tank that is going 24-7 here at home. It's been doing the small bits. They are de-rusted, scrubbed clean, wire brushed and then put in a metal prep solution for about 30 minutes before being painted and boxed up for going back on the car - hopefully very soon. Good luck, but make no hesitation - it's a very simple process, easy, and very practical.