Welcome - Mr Heaterbox and Interior Restoration Services
This company does boards for just about all old mopars, and tach boards that work with MSD type systems. They rebuilt my std cluster, but I didn't need a board. Their electronic voltage limiter is a good piece, but not sure if it is theirs or not.
Worth investigating the option anyway. They have an ebay store, but I'd call directly. It will be cheaper. They are in Canada, so shipping is a bit of a hassle and more expensive than we're used to.
Excellent service and great work but I wouldn't put their people answering the phone in a telesales gig. Extremely knowledgeable and confident in their products but have your questions ready because you won't get a sales pitch. Personally, I appreciate this approach.