DocNrock said:
Agreed on 37 mm for a recessed OFR.
"You're not ordering the FR from Warmoth? Caveat Emptor!" Jack, they are out of the black ones and last I checked very low on the gold ones; I don't know about chrome. They also don't know when their next shipment will arrive, as there have been some deaths in the Schaller family. The most recent OFR I bought I had to go outside of Warmoth.
I wasn't necessarily implying that you HAD to buy your FR's from Warmoth; as the OP didn't specify where he was ordering from, the "Caveat Emptor" was referencing the Chinese knockoffs that typically go for around $49.99 on eBay or some other internet outlets. These often come with studs that won't fit in the holes that Warmoth routes, and may have stud spacing or other dimensional anomalies from a "real" FR bridge that can preclude it fitting in the Warmoth FR routing or working properly in such.