there seems to be some handy types on this forum. that 3d printed part would make a perfect plug for sand casting a replacement part out of aluminum and being flat backed there would be no parting line. so it would be as simple pressing the plastic part up side down into a sand mold tray, striking off the flat surface, pulling out the plastic part, and pouring in molten aluminum. youtube is your friend for learning how to do this.
i don't have even a basic ' home foundry ' so i would take an even simpler route of making a rtv silicone mold and then pouring it full of glass filled resin. one silicone mold could make dozens of replacement parts before it would deteriorate enough to need replacement.
i know i know, a big waste of time and guys should just wait until the company gets around to improving the quality of the base and then ships them one. but some guys on here are handy and skilled at fabbing stuff they need so they can have it right now, and those are the guys i'm talking to.