I am not sure I agree with the notion that epoxy resins deteriorate that badly over time. If it were true then standard class(15m) fiberglass gliders made in the 80's would end of life. Which is certainly not the case. In fact, Libelles are still flying as well and they are even older as being some of the first glass ships. I suspect what we have available to us in the modeling community is not quite up to par with something like an MGS or similar.