Looked at a confusing (at least to me) pre 10 today. Hoping for some clarification and guidance. Here's what I know:

SN - S844xxx
Barrel- 6 or 6.5"
1 line Made in USA adress
Large ejection rod knob
5 screw
long action
square butt with Diamond magnas
95% condition
$799

Hi
This revolver is not really a "pre 10." It is an early postwar .38 Military & Police revolver that shipped in September or October, 1946. It would still have the long action and would, as you say, still have the barrel-shaped knob on the extractor rod. The barrel would be 6" in length, since 6.5" was not a cataloged length at that time. I do show others in that serial range with 6" barrels.
The square butt diamond Magna stocks would have the sharp shoulder as well as the diamond, if they are original.
That price is a bit high in today's market. At 95% and no box, around $500 would be more in the ball park.
Any chance of seeing photos?

__________________
Jack
SWCA #2475, SWHF #318