4d Staunton - Solid bases and other minor QoL tweaks

I am printing a set of these wonderful pieces for my local library and have made a few changes:

• Solidified the bases (no internal cone for added weight)
• Tweaked the lower jaw on the Knight's horse so there is slightly less of an aggressive cantilever
• Re-meshed the knight as I was getting manifold errors

I applied a modifier when I printed these to add a weight to the bases. I set infill to 45% in the "foot" of each piece, bar the knight who I set to 60% due to how short the "foot" is. More time and material yes, but leads to the pieces feeling weighted. I also ironed for that smooooth Knight and Rook experience. I find 95% scale is perfect for 50mm squares, personally.

Yes the 4d watermark on the underside is still there, no I will not be uploading a version without it; it hardly uses that much more time and material given the settings I am running with!