~1936 Large Marine Green VACUUM-FIL

 In 1933 Sheaffer created a sub-brand they called VACUUM-FIL. VACUUM-FIL seems to have been intended for the initial release of the vacuum filler in 1934 as a means to work out the design and manufacturing process. The first Sheaffer Balance with a vacuum filler appeared in the 1935 catalog. VACUUM-FIL renamed the WASP Pen Co in 1936.This is the largest VACUUM-FIL / WASP pen made; collectors call it OS or Oversize. It may be from the overlap of the VACUUM-FIL vs WASP eras as it has a #6 WASP nib. I have seen other pens with mixed parts that seem to give evidence of a period of transition. The nib is soft, bouncy, wet and an amazing writer. I hesitate to describe it as semi-flex because these nibs are 12 karat gold and quite thin. They provide lovely line variation under normal writing pressure but should never be pushed like a truly flexible nib.The cap band and clip ball have some pitting to the plating. The peak of the clip has an area of plating loss. The transparent barrel has dark