For your consideration is this vintage 1948-dated Jas P Marsh Corporation Chicago brass pressure gauge. The black dial is marked from 0 to 300 and has a pair of screws, one marked ‘recalibrator’ and the other marked ‘lock’. There is also a metal plate riveted in place that is etched with ‘OK” and either an M, W, or initials, and a date of 2/11/48 B. The back is marked ‘Spring f’ in orange paint. This was part of a large lot of naval and maritime items and resembles some of the gauges used on US submarines. The dial being black also seems to indicate naval usage, however, no markings can be found to confirm this. This gauge measures 5.75” at the mounting flange. The condition is good, with much tarnish from age. The glass is intact. It is untested.