I cannot see where you are - but we find this type of dish in Holland quite frequently. One reason is that similar items were used as premiums with washing powder in the 1950s. The technique is slumping flat glas in a mould with the pattern preshaped in wire. The technique was suitable for very short production runs, so suitable for premiums and occasional glass. I have one celebrating the complete electrification of the railways in 1953.
There is no documentation which tells us whodunnit. Could be Maastricht or Leerdam, or could be made in Germany or Belgium. But probably not much further afield...