The patent date, the numeric layout, and the letter P in front of the serial number, points to an instrument made by C.G Conn. This is what is called a "Stencil". Back in the 1920s, the saxophone craze had every music store wanting their name on an instrument. So, the saxophone manufactureres used their second line parts and engraved a small number of instruments for whoever was ordering them.

Here is a post with the same info

https://cafesaxophone.com/threads/saxophone-kalashens-kleartone-new-york-usa.23573/

With that very wordy explanation, it is still a Conn, made with a wonderful brass mixture during the 1920s and forward for a good 30 years. This American Brass is why a number of players prefer these older instruments.

In "As Is" condition, you could get maybe 700 or so. Then the buyer would expect to put another 400 or so into it at minimal. But then it would play wonderfully.

This is just one persons opinion.

Good Luck!