Hello Gil,
Anythining that fits a Cox will fit a Wasp. Same head threads, so all is easy. You are better off ditching the existing glow button / head once the plug burns out. The plugs are expensive and not all that readily available. Use a Galbreath Head and Nelson plug or buy a Merlin head and use their glow buttons. With either of these heads, you will probably want to decompress a little using Cox head shims.

Happy Christmas,

Andrew.