Here are two nice pieces from Europe . . . Actual postage is additional:

U-1895 German transposition incuse marked with the three triangle Hermsdorf logo - this insulator has damage as shown - but displays well. Tough small piece that was the specimen used for the U assignment. -- $6 (SOLD)

U-tbd from Sweden incuse marked IFO 56 on the ear -- appears to be made for export to the US as it has standard 1" threads. some light nibbling on the base. $8