Well I don't know about the old timer kit but I can tell you about the Bridi XLT that I'm building. After being about half way through building my XLT I found out from a bunch of folks that Bridi kits have very heavy balsa in them and most should be replaced. [:@]
So my only advise would be to look at replacing much of the kit balsa with newer stuff.
Good Luck
[8D]