necklace hallmark Casa....?

[KMRA]

Please help ID the necklace below, 38.5cm length, purchased 1930-1950:

[Traintime]

It would be a shame to let this mark go without an answer of any kind. To start, if "CASA" is correct, then we have what appears to be "?LLE?" or "??LLE?" following. I don't bring up the name Adler to ascribe a maker, but just to point out how the first apparent "L" might actually be a mis-cast/mis-stamped "D" (in he same way the "S" in "STERLING" was failed). Perhaps this might lead somewhere.