Thank you Longpull and Lambertiana!!
Lambertiana, when I see your Jack - I see an Empire Knife, and thats not being cheeky, I think that there's a possibility that Empire made that lovely Jack of yours.
Empire were more than very well known for out-contracting Knives for other Cutlery Companies, very much so like Camillus etc, Challenge was not as big as Empire Knives from what information I can gather Empire being so huge at the stage in 1918 - they were considered the largest Cutlery Company in the United States and at that stage they had over
800 different patterns available ( I didn't know you could
GET 800 different patterns

).
Knives that carried the Challenge Bridgeport Stamp were made in a short period of time .... Goins has them for just over 20 years, Levene's has them just over 30 years before the Company was sold.
I have gathered three, and then four Knives in these poor lighted photo's - ( sorry about that folks )...
The two knives on the Left ( Ebony ) have the Patent stamp
833146 on the Punches, these very similar in build- exact pin pattern exact same size - and lets not forget - these features are exact to Charlies Empire Knives.
The Mint Ebony ( far left) and Jigged Bone ( 3rd from left ) Hj's carry the
Curved CHALLENGE over CUTL.Co over BRIDGEPORT over CONN.
The Townley HJ ( 2nd left ) is stamped
TOWNLEY METALS over HARDWARE Co. over KANSAS CITY.
These are not super identical to each other, the knife on the far left - an unused / uncleaned near-Mint Challenge that has wider Long Pull, also a lot larger Swedge, the difference in the Swedge cannot be from wear when comparing to the older knives as the Swedge goes deeper down towards the Edge on this Knife ( far left ) than the Knives on the Right with the smaller more narrow Swedge - you will see what I mean in the photo's.
The Knives to the Right hand side shown in the photo's are a HJ Stamped "Challenge Bridgeport" and an Empire Girls Scout, both these knives on the right hand side carry the same Punch as each other ( the Empire Girls Scout's Punch is slightly shorter to fit the smaller frame - exact same Punch with a taken down Tang and tip-), there are no Patent numbers on these Punches and a slightly different Styled Punch with the Over-hang when compared to the Ebony Knives, you see this very clearly in Charlies post in this discussion (
post #15802 ) both Knives in Charlies post are made by Empire- ( at different times I would have a guess ) - and Charlie's two HJ'S have the two different Punches, both have the two same Punches patented to Empire Knives as the two punches on my knives shown.
I would consider this a very strong possibility also that Empire made these Challenges Knives for some time for Challenge, or even another possibility that Empire supplied parts to the Challenge Bridgeport Cutl. Co to assemble, the reason why I think this is such a strong pull towards Empire is...
1, The shear size of Empire compared to Challenge
2, The exact Same pin pattern as the Empire Knives of Charlie shown in post 15802
3, The same Bolster Style and Shape, the same low-cut Rats Tail as the Empires, and the exact same sized Rat's Tail.
4, The same type of Blade Grind as the Empires, and long Pulls.
Heres are the three HJ's
1st left is the Minty Challenge stamped Knife- this features a wider Swedge than the other two, along with wider Long Pull ( either an earlier or later production model that the other two )
A photo of the Knives closed- in the same order.
Again the Knives in the same order with the addition of a nice Empire Girl Guide's Scout Knife with the punch as another example of the Empire Punch - that matches the Lovely Jigged Bone Challenge HJ's Punch.
Now the four Punches together- keeping in the same order still..
and the Pile side of the Punches - in the same order again...
When looking at the photo's, it would be very safe to say that the one manufacturer made these three knives, now just who made them?......
Heres my summary of thoughts.
1, So in all folks we have Empire Made Knives shown by Charlie to be the exact same as the Challenge Knives, so I am asking myself what is the possibility of Challenge producing an exact same Knife as Empire with only the Punch supplied by Empire?? - exact in the pin placement, exact in size, exact Bolsters- with the exact Placement and size of the Rat's Tail? exact Blade grind, Blade size and Shape - I suspect that this is pretty slim...
2, Or...... Empire made these Knives for Challenge - which cannot be sneezed at because of the "pretty much exact knife" that these are when compared to the Empire Knives, with this Empire contract-made thousands of Knives.
3, Or.......Empire supplied the
complete package of parts to Challenge Bridgeport Cutl Co other than shields and in some cases Challenges Jigged Bone Handles for a percentage of the model output.
Just threw in this extra photo of the Comparison Knives that I had on file..