Malta Cross?

Could Forum members help to identify the small handmade silver cross in the enclosed picture. It measures 20mm x 20mm and has a small pin on the reverse and the original owners initials engraved on the lower arm. The recipient served with 108 Squadron flying out of Malta and was killed in action during July 1943.

I have seen similar insignia with squadron details engraved on the obverse. However, this example has only four letters. They read from the top: M / N / F / U

My starter guess is: Malta / Night / Fighter / Unit

Can any more knowledgeable members offer me a more definitive answer?

Kind regards, Malcolm.