In the photo I see a very small base, not much larger than the jack body, with no holes for bolts or even a likely place to add them.

thats true, but my toolmaker mind looked at it and jumped immediately to a strap or something fabbed to bolt it down. you are right they did not make a good provision for bolting it down if the finished product is as shown

I have one of those old Buda testers that look like a jack,been working great since WW2 the gauge is still good i tested it against a new Caterpillar guage a couple of years ago and it was right on the money. If you cant bolt it down sometimes i just grab it in the bench vice.For a filter mine has sort of a screen in the little cap where you fill it, i usually filter it thru a paper towel when i fill it. one thing i did do,was to drill and tap a small hole so i could vent it while filling as it was very slow to fill,much better now. My $.02 Don

I use mine mainly for checking the spray pattern of gasoline injectors now. It has seen much use in the past for Benz and off road diesels.