It appears to be an HKL sheath, not a Johnson. That being said, the rivets have been there a long time it seems, and are period, so it is difficult to say 100%. It is most probably an owner modification.

The Randall shop set keeper snaps, they didn't make sheaths or add rivets I know of, and Mike's story of adding rivets is the first I have heard of. I wouldn't think the shop even had the tools to do so. In fact, I would bet money on it.

In any case, I don't think it really detracts from the package, and I wouldn't look at it as a negative.

What is odd, is the washer/nut for a knife apparently that late, or an HKL sheath with a knife that early. Depends on how you wanna look at it.