Here is an interesting variation of Pope lubricator. This example is clearly a Pope product, but has a four pronged handle for advancing the lubricant. The patina on the handle and remainder of the tool are similar so it appears to be an original variation. Also, the screw designed to attach the tool to the loading bench is in brass; most Pope lubricators have iron or steel screws and handles for that purpose. Compare this tool with three of the more commonly seen variations. One final significant difference you will note is in the orientation of the brass "arm" which supports the return plunger; the more commonly seen tools have that support oriented orthogonal to the long axis of the tool, whereas this one is oriented along the long axis of the tool.

Here is a lubricator made by Axel Peterson. Somewhat more austere in appearance than the Pope, it has no provision for clamping the tool to the workbench. Nevertheless, these are very functional tools. Pope lubricators are difficult to find in unaltered condition, and examples made by Peterson are even harder to find.