now my OCD will demand that I complete the set.
Not worth it IMO. There was a time when it was really hard to find used Special Forces stuff. Took me a while to find a spare 3/8" drive adapter. I did find one as you can see for a reasonable price but it's a bit rusty.
Right now you can find lots of Special Forces stuff on ebay, even the drive adapters. But they ain't going for reasonable prices. No way I would pay close to any of the prices they asking. But I haven't seen those extension for sale often, then again I never pay attention for them.
I used the heck out of the ratchet. But working on cars I pretty much never had a situation where these pass throughs saved the day. The ratchet was handy cause I often would pop out the drive adapter & use it as a finger spinner, get a bolt or nut started, then tighten with the ratchet or vise versa.
I haven't used it in almost 20 yrs, I have newer & better ratchets. I keep it for the sentimental value. Again it was pretty much the 1st real ratchet I ever purchased myself. Prior to that were round head Husky USA ratchets that came in a set, which I also still have. I was never a fan of Craftsman ratchets so I never bought any during that time or ever or probably ever will.