I was able to adapt a Banggood PBT spacebar to put on my Leopold FC200R using a mod that is mentioned briefly in a few threads (and also in Ripster's image guide). Using an x-acto knife, I isolated the stem from two spare QFR keycaps. I then sanded down the original stems inside the spacebar. I placed the isolated QFR stems on the cherry stabilizers, flattened a sizeable ball of epoxy putty on each sanded area of the spacebar, and pressed the spacebar onto the stems, adjusting until the spacebar was flat. I'm not sure that the mod will hold if I try to remove the spacebar but it works! It is, however, time intensive so I would not do it again but I'm glad this fix exists.
EDIT: And AFAIK, the Banggood keycaps are Keycool keycaps. The spacebar is "universal", as in it has 4 stems, but none of them fit Leopold FC200.