Help me ID this box wrench

[J5hort]

Hi All,
I have been clearing out old tool boxes ay my parents home and ran across some wrenches that I am tring to identify.
My motivation is more sentimental value as I am trying to identify if they belonged to my grandfather who died before I was born.
Good news is that this one has his initials stamped in it, just no other markings other than box end sizes (1" x 15/16"). Shaft is completely round.
Any ideas on how to find manufacturer? Will also be interested in cleaning and protecting this from rusting again. Any recommendations on cleaning and protecting?

 

[619DioFan]

Pictures of the box ends of the wrench would be helpful.

 

[four.cycle]

^ only with clear close-up shots of any stampings/forging marks would anyone be able to make a guess.

 

[J5hort]

Sorry, upload chopped my photo. Uploading more. Just sizes stamped and grand dad's initials so far as I can see.

 

[J5hort]

Let me know if more images or closeups would help.

 

[WWheeler]

Gotta say that round shaft is a sight for sore hands to me.

The shaft on the Proto wrenches I have at work are square AF and hurt my hands like crazy on days I have to pull on them very much. I often wind up wrapping a towel around them by the end of a 12 hr shift. I really do hate them and knowing what I do now wouldn't have paid .25¢ for the entire set if it was my money but my work bought them so that's what I use. They tend to frown on much use of our own tools which is a good thing as I work around too many other people to ever have a clue if/when someone's hands get sticky. Tools disappear every single day.

I've read people here complain about Tekton's angle wrench set that are laser cut w/ CNC machining because they look more square than most but I use them at home and they very comfortable to my hands. At least they have a bevel on the edges. Pulling on the Proto feels like pulling on 3/8" steel bar stock comparatively.

tldr: That round shaft looks like it might be the most comfortable wrench I ever used to have to pull >150 ftlbs on, assuming it's strong enough to do it.

 

[Ricky Joe]

Looking at the way the ends are tapered makes me think Plomb, P&C, or maybe Penens. I have some that I find very similar to those brands, without manufacturer identification. I also have some Lakeside that I think were Plomb made with that style box end.

 

[dvblanch]

Think SK may have made some round beam box wrenches in the 60's & 70's

 

[yatg]

Have a couple that look like that. Mine are marked P&C.

 

[J5hort]

Other Plomb were in the lot, so good lead there. I will clean up with evaporust to see if there are any other markings. I plan to keep as it is marked with my grand dads initials. I may even wire wheel and finish. I probably will not use too much, but want to own as a family history piece.