Welcome to the forum.
It looks like you have an 8 3/8” barrel model 17-4 from 1980. I’m assuming you read the serial number correctly off the butt and had difficulty seeing the 8 in the smaller serial number stamping below the barrel shank. The 1980 date comes from the most used reference, The Standard Catalog of Smith & Wesson, (SCSW). The stock was made by Hogue.
I went to the range this evening so my 8 3/8” K 22 also needs a cleaning. I’m going to let the solvent soften the crud over night then clean it in the morning.
Federal Bulk pack 36 grain .22 LR shoots well in all of my k 22s. Before the hullabaloo over possible new gun laws and panic buying it was usually the least expensive .22 LR which makes it all the better.
K 22s are my favorite guns so I predict your boys will love it.