Bill,

Many thanks for the tips. I just received Jeff's answer to my question about the 3/4 X 1/2. He suggested stripping it to form the missing 1/2 X 1/2 and again to form the missing 3/8 X 1/2. Not trusting myself to cut a perfectly straight and vertical strip with a knife, I will simply laminate some 1/4 X 1/2 I have. And I think I also have some 3/8 X 1/2, so I'll avoid having to perform that surgery.

Looks like a trip to an auto parts store is called for this weekend.

Cheers,
Richard