Hi Randy,
I would check with Bill Sawyer of Windancer Models because he lists a Chipmunk canopy that I believe is for the Van Loo version and not the newer Sig version of the Chipmunk. I vaguely remember talking with him when I was buying a kit from him and I think he told me he made the canopies for guys in the cottage kit business so he may be the guy who made the canopy
for Walter. I may be wrong about that, but in any event, Bill may be your best bet for a good canopy. Hope that helps. Bill is in the Vendor section of this forum.
Good luck,
Pat Robinson