Hi Bob,
I'll write a fuller explaination when I have a moment about your 1937 HK (I'm sort of busy writing code for the Forum upgrade - WHILE IT'S LIVE!!
)...
Anyway - I'm 99% certain your HK is NOT refinished of refurbished. Based on your photos, here is what I see (and I presume that your pictures are from a scanner - NOT a digital camera. Scanner washes out the straw on the high edges - accounting for the change in tones, for example, the picture of the trigger).
Anyway - here is what I see....
1- The overall stamps/proofs are correct, as is the serialization of the parts shown. All look like they are original, and without being recut after a polish by someone refinishing. The most telling is the LWaA2 on both the frame rail and the front - right - forward of the cannon.
2- Your takedown still shows the HK buffing tell-tale. It appears correct.
3- The toggle ramps are correctly fire hardened. The thumbprint is often redone, but the toggle ramps are often overlooked. Yours are correct given what I see as to how they are done.
4- The magazine release is fireblued as well. 1937s and other production years can have either (some years more then other types noted) - BUT - if you look at the blued frame and corresponding blue of the mag release, the fireblue ages differently then the frame. Your's appear correct, as the aging of the frame blue can't be replicated and the contrasting mag release.
5- front lug area on the cannon. Excellent. Most HKs that have been "done" by expert "restorers" will have the barrel matching the blue on the barrel, especially where it is joined. Your's rather - appears correct in both tone and hue differences.
6- The GESICHERT stamp is correct, and that area has NOT been tampered with. The die stamp, in 1937 - shows the wear points and die-roll over you see on yours. If your HK was "redone" - that definition would be lost.
7- The toggle stamp looks absolutely correct. The last "F" would roll off. I'm interested in a better photo of the side of the center toggle to be certain, but yours appears correct and original in the photo that I can see.
8- Chamber Date. The depth and the "3" as a descender is absolutely correct. As well, the die stamps and serifs look correct, as does their original depth and sharpness.
Anyway - again, let me take a closer look tomorrow. As well - if you'd like it verified, please feel free to send me a PM, and I can make arrangements to look at it in person, if you'd like....
Hope this helps!
John D.