WGB
(A retouch) "affecting the Top Left Frame junction Line and Line 1 Upper Left: 3UR8, 3LR3, 3LR10 and 3LR93, 4UL41, 4LL9, 4LR67, 4LR78 and 4LR93"
WGB
The stamp illustrated could be any of ~ 3UR8, 3LR3, 3LR10 and 3LR93, 4UL41, 4LL9, 4LR67, 4LR78 and 4LR93.