[amsat-bb] Problem with original AMSAT Satellite RX preamp

I have one of the Original AMSAT Broadband Satellite RX Preamps which has quit functioning. I have checked most of the components and everything looks normal except there is a large loss of signal instead gain. I suspect the Mini-Circuits MAR-07 has failed. Both Mouser and Digikey list the part as discontinued and zero stock.

Is there a source for quantity 1-2 each of the part, or does the AMSAT group that builds it have the part available?

Or is a substitute available?

Ron W5RKN