Unusual 10" artillery luger

[Ray]

I recently purchased this artillery. It appears to be a 1923 commerical luger in the 82,000 serial range. I tried to photograph it in natural light (not a lot of that up here in Oregon this time of the year) to best examine the finish. What can you tell me about it. The front sight blade looks odd and the bbl lacks a serial number, just a crown N proof. I'm guessing that this piece started off as a regular 8" artillery that had the bbl changed at
some time perhaps in the 20s. I was estimating the finish at about 60%.