Variant of the BTMC 2724. Made for PTT after WW2. Please note the uncommon dial centre with the small number window and the letter K over the 0. That is typical for Dutch telephones from the 30s and 40s.
The Dutch version differs on the inside from the 2724 too.
First this phone was produced by BTMC in Antwerp, later is was also produced by NSEM in Rijkswijk (South Holland province).