I may have mentioned this to you before, but a local glider pilot owns a

Schweizer 1-20. I'm not certain that it is 100% 1-20 parts but it looks

very much like your glider.

I have a web page for Roger's glider on my 1-20 site:

http://www.gfbyars.com/SGU1-20/n37hh.html

His glider was originally a 1-19, but was converted to a 1-20 some time
later. NX-91840 was the only "factory" 1-20.

Guy