Hi Anne and group:

we found a number of similar cups with the same Swedish base mark at a
1924-1925 dam construction camp in the northern Sierra Nevada, CA.  We
weren't able to track the mark.  As far as the mark being from IKEA and
post-1950... the artifacts from our site were innundated with fresh water
soon after the dam was constructed (by 1926) and remained under 70+ feet of
water until 1996 when the water level was lowered to repair the leaking dam.
We were out recording the deposits before the mud dried and the site was
closed off and patrolled before we arrived.  We had many examples with this
mark in tightly dated mid-1920s deposits and found no "modern" material, with
the exception of an occasional fishing lure.

Mary Maniery
PAR Environmental