Micro-Belmont will make whatever you may need, on the other hand I don't see why the IQR couldn't me made to work. I don't have a PRO in the garage but have numerous IQR's that I could measure. There was a post on here yesterday of a guy that had got a splined PRO secondary by mistake and was looking to trade for a Keyed IQR style. If that by chance is the issue? Good Luck