The stainless screws are not the problem, the
bronze sail track is. Stainless is fairly close to
aluminum on the Galvanic scale, bronze is a long ways away and thus very reactive with the mast.
I've got a slightly newer Pearson (1969) and have removed all the fastenings and
hardware on the mast. I've reinstalled it with TefGel for the fasteners and plastic
insulation material backing the
hardware. Surprizingly, the corrosion was relatively mild even where the bronze goose neck track was against the mast without any
insulation.
If you do decide to R&R the mast hardware, an impact screwdriver is a real plus. I've got a 12 volt Hitachi and it's been a god send in getting recalcitrant fasteners loose. Buy lots of straight slot bits as you'll shatter a few.
Another trick is to use
battery cables and the
boats battery to heat the fasteners. Put an appropriate sized machine screw or bolt in the positive clamp. Attache the negative to the mast as close to the fastener as possible; hold it against the mast right next to the fastener; or, if you are lucky enough to have access to both ends of the fastener, touch or clamp it to the opposite end of the fastener. The dead short created will heat the fastener and primarily the fastener real quick. It's essentially an
arc welder so be aware you could weld the fastener in the jumper cable to the
head of the fastener in the mast. I've never done it but the fastener to fastener union did get a bit sticky in a couple of instance. I've used this method to get a bunch of fasteners out of the mast and my
self steering without a problem. Until I learned this trick, had a number of fasteners I couldn't get out or broke the fastener. Using this technique, I haven't found a fastener I can't remove with the help of my trusty impact screw driver. It may not
work first try so have patience. Heat the fastener, spray with penetrating
oil, heat again and repeat till the fastener comes loose. May take a couple of overnight soaks in penetrating
oil for really corroded fasteners.
FWIW, the threads were all still good in the aluminum on these long corroded in place fasteners.