Crosman Model-137

Crosman Model-137 (boxed) 

Pics copyright Holts Auctioneers.

Crosman Model-137 reseal 

With thanks to Louis.

He says:

I hadn't seen this type of "front sight pin" yet.

Turns out to be a steel cap on both sides, to hide the rollpin. A nice detail.

Disassembly. The two halves of the valve needed a little bit of force to turn loose.

Some verdigris inside the valve.

I like it that the barrel can be removed from the ally breech with a tidy little screw.
On later 130's, this is not the case; barrels are bouned/glued into the steel breech (early pistols had those nice ally touches).

I cleaned everything in hot water with Fairy liquid. Then dried, with a towel and q-tips.

Another example of the pistol's quality: the headspace of the pump head can easily be adjusted.
It was overcamming too much, which made pumping unnecessarily hard.
Now the head just touches the valve face, click, pumparm closed, nice and easy.
I usually leave the pumpcups in "transmission oil stop leak" overnight. Not sure if it helps, but it is one of these routines.

He adds:

The 137 is doing 390 ft/s with 7.0 gr RWS Meisterkugeln at 6 pumps, after a full reseal. 
Not a lot, but plenty for my 5-10 meter indoor fun shooting. 

Whilst testing, I felt quite some air escaping from the probe area. Maybe also around the barrel. 
I put some blue Loctite on the barrel, to improve the seal. Not sure if this is a good idea, but it will still be easy enough to take apart. 
I also put some ptfe tape under the probe o-ring, as the lockup of the probe wasn't tight enough imo. I used a slightly thicker o-ring than in Rick's seal kit. 
It feels a lot more positive now. Will test velocity again soon.