"A 1981 K-22 might have been shipped with standard Magna (service) stocks, or Target stocks with a larger ("speedloader") cutout on the left panel. The ones on it now have the smaller "football" or extractor cutout."
Murphydog
Here's a 17-4 in the 33K8xxx range. '78-'79 mfg gun with the magnas he's talkin' about... (there's a K-38 on top.)
I put target stocks on my shooters, though. You could just leave the diamonds on. Class is never wrong.
GF