what have I found

I am able to answer my own question now but never having seen one before I wondered how many other have.... (been in my shed for years) and knowing what it is, I have no idea where they were used.... or why they are numbered....so I thought I would ask anyway.
Are they rare.... (read valuable)????
The hammer head is for size reference only






As you can see they are very similar, but one is a cast iron case and the other brass
The plunger is spring loaded to the position it is in now... if you pull, it is against the spring and will return to present position. Both have a grub screw in the hex head bit.

They might be some type of Oiler Sarge, & the Grub Screw controls the Drip rate..

Petrol primers for early engines.?

What about bearing oilers for a steam engine, just a guess

Wot U have found Sarge :-X
could/would/should B a aoto lubricator
the new V: looks like this as Used on conveyor belt rollers etc









WotSezU?
cya

Since you have suggested that they are plungers on top they cannot be petrol primers as they would blow apart once the engine started up. Definitely an oiler and the plunger can force the oil to the point where it needs it and then maybe the small part sticking out near the bottom is a drip rate.

If the handles were T shaped, I would have said automatic greasers. We still have a few jobs at work with them. Pull the handle all the way against the spring, turn 1/4 turn (maybe those ones have a slotted hole like a grease gun?) fill with grease, screw back on, then release handle. As mentioned, the screw adjusts the rate of flow.

Jarrod.

Sorry, been away, Jarrod and Swish the closest, in fact Jarrod talked himself out of it..... otherwise you were all on track. I first thought a fuel primer, then oiler, but not spring loaded, then decided to ask on here. Had a light bulb moment and unscrewed one first....





as you can see one has not seen new grease in a very long time....
I tried pull back and twist, like a grease gun, no twist. the shaft has a rib along it preventing any turn. I guess you hold it fully open while the apprentice stuffs grease in the cylinder.

I recall some old tractor that had a row of oilers/grease caps on copper lines just in front of the steering wheel, perhaps these are numbered for a similar purpose.

now to give them a new home.

Beers all round....

You can still buy them new and I have some on one of my hit n miss engines. Some look the same and others are totally different.

You may find hard grease behind the cup preventing you from pulling them the whole way out.

Jarrod.