G'Day Derek, the pivot pin on the brakes should just push out, but if it's stiff you may need to carefully tap it out with a soft aluminum or copper drift, then clean it up on a wire wheel and use some good grease or anti sieze compound.
35mm fork legs come in different lengths, depending on the model they come off. F2 fork legs will work, but they're longer, as are K7/8 legs, and I think 900F legs are longer again. I used Suzuki GS750 tubes (better dampers) on my K1 and they were a good inch longer than the K3-6 legs I'd been using prior.
Your new fork brace isn't a fork brace as such, it's a chopper "Tweek bar" that clamps onto the extended fork tubes (not the sliders) on a chopper about half way between the lower triple and the front wheel, to reduce fork flex. Sadly it won't do you much good on a normal bike, it'll just reduce your fork travel, with a thump. Cheers, Terry.