If cost is a big concern, trying out multiple used blocks might be cheaper than milling your own.

eg. sandwiching a couple MCW5002's, 6002's, Maze4's or even some ancient MCW462's/Maze3's with a TEC in between.

Just (if needed) sand down the pressure "bumps," lap 'em, bolt a TEC between 'em, insulate, and away you go. I have no idea what Martin charges for milling in comparison, but 4 blocks could probably be bought for around $80-$100 shipped.

It won't look as cool or fit as nicely, but things usually don't when cost is a concern (ie. function over form)