Dad, first beautiful car. I commend you for NOT jacking the back and doing all the things folks do to that style Fury to race it. I am a stickler for originality as well with few exceptions. I sometimes get the look of "why bother" but I say because that is the way I want it.
So good for you keeping it original.
The one thing I would kind of agree with however is the dual master. I have a 67 and one side went shortly after I bought it. Believe me it can happen. Had I not had the rear at least I would have been in trouble. Having said that, if you still want the original MC, good for you, do it!
Now as far as keeping the old cap, the ONLY thing I have found to work on rust is Naval Jelly. available at Lowes or Home Depot.
As soon as you brush this thick goo on, you can see it bubbling. Wear gloves.
https://jet.com/product/f084d4f4611...a07f248e5706&gclid=CKP-icnMlMcCFYEYHwod54ALig
The only other item is this stuff I have seen from Harbor Freight called Evapo-Rust. In Googling it, I see Wally World has it as well.
http://www.walmart.com/ip/32OZ-Evap...93344209&wl4=&wl5=pla&wl6=88700477049&veh=sem
It is expensive IMHO. $7.00 for 32 oz. That is 128 oz for a gallon and it gets pricey and since it is a liquid not a paste like the Naval Jelly, you have to use a lot.
Fine for nuts and bolts but if you have to soak the cover for example, you'd need the entire 32 oz I would think, you cant brush it on.
Good luck either way and again, that car looks great.
