The lens is ASAHI PENTAX TAKUMAR 105mm f/2.8, M42 mount. I bought it from an eBay seller in Japan.
24M Mar 11 09:40 DSC00374.ARW
28M Mar 11 09:56 DSC00374.png
35M Mar 11 10:55 DSC00374-M.png
I created a 6k (6024×4024) image using ufraw, then loaded it to GIMP to do simple color correction and exported it to 4k image.
Ran the following Imagemagik command to crop.
$ convert DSC00374-M.png -crop 1345×1530+1400+316 watch-m0.jpg
f/4, 1/30s, ISO 800, two florescent bulbs on the ceiling.