I made a card holder to lay as part of the board, which is a remix combo of the 2 models found below. 

Compatible with these interlocking base hex pieces https://www.thingiverse.com/thing:3700300

The resource tiles are found here which lay on the base hex pieces
https://www.thingiverse.com/thing:2525047/files

I will look to create a card holder for those that aren't using the interlocking hex bases, if someone requests it.