First, thanks for your comments!
I‘d like to clarify that it isn‘t my concern to blame former owners or builder of my plane. Especially the original builder did a great job in 1995 and realized nice details which are still here today - 25 years later! Me so far, I did only tear down things to see and certainly learn to get a reasonable rebuilt done- someday! Not in position to point at somebody...
Thanks Lowell for the insight into the world of tail-airfoiling! I will check and see what I could adapt/realize. Overall I‘m in need to save some weight, means the plane is too heavy at the moment...