Small antique cast iron pressure gauge with brass plated trim in original case with 3 needles

This is a beautifully preserved, turn of the century set that includes a pressure gauge, three needles, and a lined leather case.

The pressure gauge is made from cast iron with a brass plated trim that shows a bit of rubbing. It has a classic crescent indicator needle set against a white metallic face. Its diameter is nearly 5.5 cm.

It has the makers mark printed on the face, that appears to be 'H i', however it is not very clear and difficult to read and no amount of searching have found a similar marking. It is also marked 'LBS. PER square inches' and has the number 508053 which could either be the patent or inventory number. 

Included in this set are three needles of varying length. As it is not 100% certain what the purpose was of this gauge (other than measuring air pressure, of course) one can but only speculate at the need for three different sized needles. They measure 3 cm, 2 cm, and 1.5 cm respectively. 

All of these items are neatly stored in their original, custom made case that is covered with black leather and lined with blue velvet. The case is in a very good vintage condition with all hardware working perfectly. It measures approximately 7 cm X 12 cm with a height of about 4 cm.

A great collector's item in a very good condition considering its age.