Ux7 Postcard Missing Teeth

I came across this interesting item missing 2 teeth at bottom of frame. Any one else with missing teeth? Also what is with the A cancel?

The "A" is a station mark where the card was received. This thread has other examples:
https://goscf.com/t/71937

These early postal cards have numerous plate varieties in addition to poor printing quality. It would be useful to see a close-up scan of just the stamped area of this card to see how closely it matches the S6d ("ONE CENT" re-entry) variety listed in the United Postal Stationery Society's catalog on postal cards.

here is close up.

[Per note in the catalog the toothed border below the stamp was "peculiar subject to wear; copies are frequently found with teeth defective or missing". Plate varieties are discussed in the journal Postal Stationery OCT-DEC 1996, pgs160-162

here is another, almost toothless!