Thanks!
Here’s a great (and funny) one: http://youtu.be/Tka2edyZf4o
Basically you (1) cut the foam to size (leave a little extra on each side for a snug fit), (2) measure out each hole, (3) cut the holes using a tin can/cookie cutter, whatever. And that’s pretty much it. I’ve done this method several times now, for a handful of cases and now these displays, and it can be tedious at first, but you get the hang of it after some trial and error. If you mainly have throws that have a sub ~53 diameter, you may want to find something that hugs a little tighter than the tomato paste can. Star-shaped cookie cutters do well, I think.