Hi, Scott! You noted that you want them 1 3/4 inches square, but you didn't note the thickness.
If you're looking for relatively thin bases, as opposed to pedestal bases like the one in the image in your first post, you might just want to get yourself a piece of luan plywood at Home Depot or Lowe's, or any other hardware store, and rip the bases yourself. They work out to a finished thickness around 3/16". HD and Lowe's both sell smaller sheets, too, so you wouldn't have to buy a full 4x8' sheet. You can get a 4x4' piece, for example. I've bought them in the past for things like that. If you have a table saw, then it's just a matter of setting your rip fence for the width, ripping the stock into lengths, and then another pass to cut the final size bases that you want.
Hope that helps, prost!
Brad