Pin diodes have a lot going for them. I like them.
What I have to try is two of the filters from the board and using the
poor mans pin the 1n4007 diode in pairs two on each side back to back.
Worth a try and what is the cost if it fails.... not much. For two filters
and 8 diodes its maybe 20cents in parts.
I've used that to 5W for TR switching with good result.