M1 Carbine Barrel Marking?

[mkneill21]

I recently bought a Standard Products M1 Carbine. I've had many carbines but I have never seen a barrel with this marking. Can anyone tell me the manufacturer of this barrel?

Thanks

https://photos.app.goo.gl/yRF4ZJLmDEAQbc3m9

[RDS]

Are there any other marking on the barrel? Have you stripped it down to barreled action and checked barrel flats. Also slide the barrel band and see if any markings underneath it.
If you find other markings please post photos.

[mkneill21]

There are no marks under the barrel band, but closer to the receiver there are 3 marks. There is also a P stamped up by the muzzle.

See attached pics

https://photos.app.goo.gl/np2VfnczyRkAqyBk9

https://photos.app.goo.gl/QFyjHcNGv1igYFvT7

https://photos.app.goo.gl/82tgTBecCcsfcGbo6

Appreciate the help

Edit - There is also a crossed cannon stamp on the bottom flat of the barrel right by the receiver.

[RDS]

Can you post a photo of the muzzle. Also please remove the slide and post photo of barrel flat and gas block.