I found a gasket/diaphragm set to fit the Walbro on my TOC-53 at a local John Deere dealer. It's an Oregon brand aftermarket replacement kit for Walbro p/n D20WAT that cost $7.50. The package had a number of parts that weren't applicable, but had what I needed. Baffling is currently in progress, hope to get a few (successful) flights in this weekend.