For those with lots of time and little money:

Go Experimental!

Deregister the glider, disassemble the thing to some degree
(51%)....take pictures, put in some new parts, rivets etc and Build an
experimental glider out of the parts you have available......Call it
what ever you like, probably anything but Pegasus, register it, test
fly, get COA and now you have a glider with little resale value but
lots of fun value......

Oh and by the way, apply for your repairman rating as well since you
built this aircraft and are now qualified to do all the annuals on it.

For those with lots of money:

Mount it on a pole at your local glider club along with your club
banner and buy a new glider!

For those that like to fight and get bloodied:

Hire a french lawyer and ask him to drain you of surplus cash and get
bloody irritated for a couple years so that you will grow to hate your
Pegasus.....which you will eventually leave abandoned for all the
rodents on your airfield to make their home.....better there than in
your new glider right?!

Looks like a pain no matter which way you take it!

Sorry your options look grim....perhaps its just time to move on and
enjoy flying rather than beating a dead horse.