R.A.A.F Crystal Unit Holder Y110X

As a part of cleaning up the remnants of Max Howden Crystals, I have come across this R.A.A.F Crystal Unit Holder Y110X in its original box.

RAAF Crystal Holder Y110X
RAAF Crystal Holder Y110X

The crystal unit is the holder only without an actual crystal or frequency assigned. I imagine that this was held in preparation for orders from the R.A.A.F for specific frequency crystals to be made and mounted.

R.A.A.F Crystal Unit Holder Y110X War Memorial

This is a similar crystal holder noted at the Australian War Memorial.

The reference page is https://www.awm.gov.au/collection/C259365

The text at the War Memorial Page includes estimated manufacture dates c.1939-1945 as a World War II technology.