Timing gears and chain

All the old 1923 to 1926 motors that I have stripped I have found the timing chain stretched to the max and a lot of wear on the timing gears. I have heard that new chains are available but what can you do about the bad chatter and wear on the gears? What have others done? Is it possible to take a 5thou lick off the teeth?
I stripped a motor recently and was surprised to find a near perfect aux shaft that had very little wear at the water pump. The pistons had a expander kit at the bottom of the skirt - a circular rod that is adjusted to expand the worn piston a few thou. Heard of them but never seen them till now. I believe they would tighten the piston in the bore and reduce some piston slap noise and considering the low kms we do a year, would put off a major rebuild for a few years. Has anyone used them? 
Has anyone found any modern distributors, rotas, caps and points to fit the early Hudsons? Barry