It has been a while since I have really been active on the forum, I bought a house and that has left wrench collecting on the back burner.  I have been looking for this Billings and Spencer 500 wrench for about a year and found it casually looking on eBay.  I believe it goes to an early motorcycle tool kit.  I believe the face markings put this wrench between 1910 and 1926.
My question is the special on the shank.  Is this an odd size wrench and does it differ from the standard 500 wrench from Billings? 
I can find no standard size for a 500 wrench; I have seen other 500 marked wrenches on eBay that were 3/8 x 1/2.   Does anyone know the standard size for a 500 wrench?
  I also received a 490 Billings wrench as well and the same seller had a Billings 485 special and he said they were from a machinist tool box from an estate.  Are these special machine wrenches?
Looking for any information
Thank You,
Kirk

Quote..............and found it casually looking on eBay.............I.E he prob. stole it because the seller didnt have it listed properly so good for you H.M. Glad that you found something you were looking for

I do not have a Billings catalog, but perhaps their numbering system is different than others.  In my 1950 Williams catalog, the No. 500 is a single end set screw wrench, 3/16 inch, which is consistent with other catalogs that I have (Bonney, etc.).  Your wrenches are both engineers' wrenches.  In the Williams, the 3/8, 1/2 would be the 723A.

In my 1940's era book, the B&S 500 series from 500 to 511 is for single ended set screw wrenches. 500 is 3/16, 3 inches long, with a 22.5 degree head angle.

It is possible it is special because it has 2 ends....
the DOE set screw wrenches are 523-541, 554-568 are tool post wrenches...


PS: The dot after each letter in S.P.L leads me to wonder if it stands for something other than Special....

Thank you all for your replies, I believe you may  be  right and this may not be wrench I am looking for.  I have not been able to find any early Billings information or Catalogs.  I also now believe the SPL means something else as the seller I bought it from just listed another wrench that is a 485.  So , I guess I am still looking and I payed way to much for this one , not a steal at all.

Thanks,
Kirk

Your list says B & S double open end wrench, which is what you have.  I think you have the correct wrench, but for some reason it was numbered 500 for the tool kit. 

Someone can correct me if I an wrong, but most of the tool kit wrenches I have seen were double open ended engineer's wrenches like yours.  The set screw wrenches typically came with machinery and were for adjusting parts of the machine that had the square head set screws.

I think S.P.L. is someones initials.

A wrench manufacturer would have one designated marking punch to make that mark if they were marking a lot of them in succession. The letters are not lined up on the 485, indicating to me at least, that the letters/dots were done individually. Also, notice the variance in depth of each letter, another good indicator of individual marking of each letter.

Just my $.02, FWIW

On a somewhat different tack...Is there any possability that that wrench was on one point in time an S-wrench? (And then upgraded in later toolkits to a straight wrench)
I wonder, because other manufacturers used the 500 series numbers for S-wrenches.....

Billings Pre ISN numbrs are very screwy btw, they liked to make their own path....
So, if it is a number from an older numbering system, it could be anything (Tho the size markings on it certainly are consistant with a set screw wrench, and it's an older one, it has parabolic openings, later set screw wrenches from B&S are very consistant about having square milled openings.....

Thanks Key keeper noticing the SPL It is somewhat crooked etc and may have been hand stamped. Thanks vtools I now understand what the set lettering is on the 490 wrench.

Thanks Rusty for your insight  this is an  odd wrench.  The wrench  has never been a curved wrench , here is the parts book photo(drawing from 1911) Somewhere , I have the 1913 parts book photo and it is the same.

This is also an odd kit because nothing seems to be from the same manufacturer.  You have Billings, Wakefield, Mossberg and who knows who else.

Thanks,
Kirk