Modern ARFs are getting much better then earlier ones. some of the new ARFs need no parts replacement.

Generally you will want to improve fuelproofing at the firewall. One quick sprayed coat of whatever it is that they apply just isn't adequate. Paint it with 2 hour epoxy and you KNOW its fuelproof.

I've got one example of a plane that needs no replacemts, unless you are sticking on an oversize engine. The Great Planes Fokker Dr1. Even the fuelproofing on this one needed no help. (very rare... I didn't paint the firewall with epoxy on this one.) My plane is mow over 1 1/2 years old, has had over 10 gallons through the .91 4-stroke I put on (oversize engine...) and it has put up with an amazing amount of abuse. Yes... when I landed on the wingtips I had to do major repairs... but thats kind of expected.

L8r... going triplane flying.

******

I might add... For a Lanier Comet or Slow Comet... you start by replacing the wings... then you replace the fuselage.... (its ALL junk)