Found a Source for 10” rear drums with 1-3/4” shoe
This is a little delayed but, I got mine in two or three days from Rock Auto. I think the price was $29 each and shipping, I know the total was under $70. They fit perfect with the rally wheels I have. This drum doesn't come up on Rock Auto when you search by the car model and size, you have to use the part number. It's a bit sketchy because the size isn't listed in the description. I was concerned about ordering them at first but I figured I had nothing to loose because I couldn't get them locally so this was my last shot with changing to the big bolt pattern.
The part number is 123.63044 and other than drum brake with a manufacture of CENTRIC there is nothing in the description that tells you it is a 10 x 1 3/4 rear brake drum but it is and it worked for my car. Summit is selling the same part for $48 so I would go with Rock Auto.
Thanks again to the originator of this post, it saved me!