It sure looks like a single plane intake by looking at the casting on the underside. Here's a couple photos of the Weiand.
I have never heard or seen a Edelbrock Poly intake.
Welcome to the site. There are many active parts sale and wanted forums here. Just look in the Marketplace forums for the proper forum and place a free ad. It is easier to ask for an item or two at a time so things don't get so confusing. Read and follow the ad rules there. Good luck.
Sorry, no. They have a 9 1/2" clutch. The aftermatket and the factory 10" A100 clutch has a scalloped pressure plate and special attaching bolts, that works on the
9 1/2" flywheel.
10,62 made. 4874 were 4 speeds. I feel the price is a bit strong. The sad thing about those cars, like many models, you can easily put $30,000+ in a restoration and they are not worth that when you are done. It has to be a passion project.