Epoxy is one of the worst for heating up while curing, (good stuff just gets hot!) you will need a slow drying resin to not deform the hull with the heat given off during the curing process, Polyester resins can fill that need but there not really the best not actually being water proof with out a protective gel or wax coat.
If i was honest ( haha normally am) i wouldn't bother not with ABS anyway, not a great material to cast off lot of issues and even the so called experts cant get it right all the time, you have a few other options, one would be to make a full plug of the hull taking measurements off the original and create a plank on frame or a foam plug coated with p38 to get your mould off of, and then cast a hull with a gel coat using epoxy resin.
Expensive and time consuming, and that's if you have the ability's to copy the hull accurately for the original,
If it was me i would just be careful with the boat, dents and scrapes can be sorted with p38 and a touch up of paint. and when it finally is time to retire her, just buy a whole new (different) yacht, there are so many hulls out there you can buy of similar shapes, the chances are you may be able to take the sails and running gear of the original and put on a new hull, if its a IOM size then you will have no issues finding replacement hulls, fairwind (800mm) classes are out there too, there are also a ton of other hulls, A class J class ( at cost) and all the other shapes i have missed.
You must be aware that some boats were not designed to live forever, (you find most abs boats are cheaper, for the main reason to get people to buy cheap = profit for many nowadays) ... and it would be foolish to think an abs hull will live as long as a GRP hull under normal use, (the regularly bangs and bumps) given the cost of many yachts ,kits and blank hulls out there i'm pretty sure you can find a 'similar replacement' or have a fresh start with 'salvaged parts'.
Don't get me wrong abs hulls can live forever if taken care off but really its a poor material to make any boat of sizes over 500mm, anything over i would be expecting wood, laminated or GRP cast.
Well that was long winded (and probably didn't make any sence)... you can ignore it, i'm babbling tonight!