The FM828 was a very successful mobile two way radio made in the thousands. I have all the circuits and many articles on the radio available on computer and will upload as soon as possible.

For starters the crystal information...

Note a few radios were produced with the non standard IF of 10.8 MHz. It is important to check that you have the 10.7 MHz IF which is the most likely.

Transmitter Crystal Specifications

Crystal Type 9681 Type Q16A

Crystal Frequency = Carrier frequency divided by 8

Receiver Crystal Specifications

Crystal Type 9691 Type Q16A

Crystal Frequency A & B Band = Carrier frequency - 10.7 then divided by 3
Crystal Frequency E          Band = Carrier frequency + 10.7 then divided by 2

10.8 MHz IF

Transmitter crystal is the same as the 10.7 MHz IF

Receiver Crystal Specifications for 10.8 MHz is as above for 10.7 MHz IF just substitute 10.8 for 10.7.