ID For 3 Company Initials Used On Dated Precancels

Here are three stamps with dated precancels, for which I am looking to identify the mailer (company) that are identified by the initials:



In particular, "Sinc.", seems to be an odd one (to me anyway). A search for JHW in Buffalo, brings me to a JH Williams Company that was a maker of tools and had catalogs issued around the time date of the stamp, so that may very well be the ID for the second stamp. The third stamp, "CSC" from Spring Valley, NY, I have no absolutely no idea about.

Any help will be appreciated. Thanks.

Could be Cleveland Steel Canal Boat Co. built boats for erie canal; known by CSC just maybe wt1

Spring Valley, CSC is Consolidated Stamp Co. issues from 1938-47.

Buffalo, JHW is John H. Williams Co. tool casting 1938-40.

"Sinc." is not listed in New York, however, there is a "SInc" used from 1938-39 in Rochester, but company is not identified.

Odds are good that that is an unidentified dated handstamp and is a good chance that what I've mention makes both the same.

Is it possible to measure the height of date & letters in millimeters.

This is why I need more reference books, so I don't make silly guesses.

Warrehouse:

Thanks for the info. At least I got the John H. Williams Co. right!

As for the NY precancel with "Sinc.", I'm never very good at exact measurements of letters that small, so I put a ruler next to it and scan the area below. It looks to me as if it's 2.5 mm but you may determine otherwise.



The first thing that came to my memory when I saw "Sinc." was the old Sinclair Oil Co. that used to use the "Dino" dinosaur as it's ad logo. That's dating me back to my early childhood days in the 1960's and I know they left the northeast US region but were prevalent in other parts of the country and by now have probably merged several times over. I just wonder if that could be the company (?)

I'm thinking it is a company that starts with "S" & "inc" may simply be incorperated.

The overprint is Control style C-23.

"Sinc" could also stand for "Sinclair" - as in petroleum maybe?

Frankie