I would recommend Mike Morse, owner of VINTAGE BRAKE, in Sonora, CA. I had a DG200 with a 5'Tost that had next to no stopping power. He has the backing plate for the 5' TOST and you can either send him your wheel itself, or send him a REALLY accurate ID measurement. He'll do the rest. The FERODO shoes were $20, and his labor was $36.... your glider will stop. I can now put the nose into the pavement. The brake does not seem to fade either, by the way. Mike is a great guy to work with, and I'm sure you'll get results.
Http://www.vintagebrake.com