Old unit is duff but saved for parts etc... PA module still fine as are the rest of the bits.
After a PSU went high a few years back finally found a decent (cheap) 2nd hand FT817 unit.
Transfered the 500Hz cw filter and TXCO-9 module easily...
I bought the TXCO-9 for a fraction of the cost of the 'official' unit from AliExpress I just looked prices are even lower now... $16 not $21 which was what I paid originally. Works fine.
I'll use this for satellite working and as a uWave transverter.