Some time back I had a chance of getting one of these but it wasn't in the best of order although it appeared complete asside from a pivot pin fashioned from a nail. The metalwork was rusty pretty much all over except for the trigger guard. The stock had lost areas of finish but the chequering & forend grooves were undamaged. There was damage to the heel & toe where it had stood on a hard surface but there seemed plenty of wood there to regain the original profile. Oh, & it didn't seem to want to cock, it felt pretty solid with no movement to the piston on the start of the cocking stroke. I diddnt try to force it but it was locked up tightly.
Never owned a Relum, but I wondered how this one might turn out with a bit of time applied to it.

Stock off, easy.
Trigger mechanism, two pins,a spring, trigger & sear, ok.
Underlever & cocking link, funny leaf spring through a guide under the cylinder, bit of a fiddle but out & clear.
End cap, pin, mainspring(s) & piston next. Spring compressor set up & ok. All ok but the piston was really tightly held in the cylinder. Lots of tapping with drifts etc after a squirt of two of fluid. Eventually it came out. Shiny rear portion, tooling marks all over it, no burrs,just grooves, irregular, horrid marks.
That's when I was surprised by what I found, the skirt of the piston was round but a greater diameter than the bore of the cylinder. Measured on a digital caliper. I can't be certain that it's the original piston/cylinder combination but it looked like it. If so I don't see how this thing ever worked in the first place. Additionally the blob on the underside of the piston which runs in the cocking slot was a tight fit too. Oh, the cylinder was round as well, it hadn't been squashed in a vice or bashed out of true.

Has anyone seen this sort of thing before?

So the tail of the pistons been reduced a fraction to get a sliding fit in the cylinder, it didn't need much off it, but it was more than a polish.

Still wondering about using a one spring set up, just leaving out the inner one rather than finding an alternative to the original pair, which by the way look dead straight no kinks etc. ( maybe not surprising if it wasn't possible to cock it).

Cleaned up the major parts of the metalwork with wire wool & oil. They look pretty fair, not deep rich polished gun blue more of a slightly matt utilitarian blackened finish. We're they polished & shiny when new or were they matt, more of a satin sheen?

Need to have a think now because when I was looking at the barrel/cylinder I noticed there was a wobble. The joint between the two is loose & I need to have a look at that before long. Wondering what will sort it out, oversized pin in the same spot as the original, seperate the two dimple the barrel & drive it back in, shim, epoxy,,solder, braze, machine a collar & weld it or weld it. Or a combination of a couple.

Pretty determined to get it working, working well would be better, don't want to spend too much money on it but I don't mind putting in some time, oh & the stocks to do.

Any one else cured a wobbly barrel, appart from getting rid of it & bbuying anothe Relum.

Not my favourite make but something to keep me occupied for a while!
Cheers