Like all things Tool Kits, there is no simple answer, DEPENDING on how accurate or otherwise you wish to be…
The GREASE GUN as fitted to all SS-Jaguar, 1936MY to 1940MY was a TECALEMIT ‘POM POM’ Gun.
Trouble is, the Tecalemit POM POM Gun was made from 1930s up until at least late 1950s, and evolved considerably over that 30 year time period withy respect to its manufacturing detail and indeed its finish.
Also the POM POM Gun was offered with a choice of three interchangeable, screw on CONNECTORS.
So for an SS Jaguar, first issue to ascertain is what specific age is your car, as the correct Grease Gun for a 1936MY car is not the same as for a 1940MY car, and variations in between, including having a painted (two different colours) or a Nickel Plated finish.
Same comment about the CONNECTOR, although less differences, with earlier cars having a TECAZERK Connector, and at this stage I believe at some very late point, so most probably for 1940MY cars they now had a HYDRAULIC Connector, noting the pre-war Hydraulic Connector was basically the same overall/dimensionally as that fitted to a Mark IV PLASTIGUN, but still with a significant visual; difference.
I dont have a good photo (side by side) of the two different CONNECTORS in question for SS Jaguar, but they are as shown on this following picture from a 1941 Tecalemit Catalogue…
The TECAZERK was as fitted to early SS Jaguar Pom Pom Grease Guns, with the HYDRAULIC as fitted to ALL post war Mark IV PLASTIGUNS, but also I believe to ‘late’ SS Jaguar Pom Pom Grease Guns, but at this stage of my resercah I cannot offer any confident demarcation apart from ‘late’.
PS. This 1941 Catalogue refers to these as “Nozzles” whereas post-war Tecalemit Catalogues now refer to them as “Connectors” which is the term I prefer, as “Nozzle” is now used for other totally different items.