Hello. thanks for the feedback and the welcome to KCA. This si my frist and only Krag att this time. I primarily look to collect .22 trainers of all walks.  Here are some answers to questions.
The barrel is a .22 barrel. Not a lined .30 barrel.

The "lobe" is connected to the striker rod and does not rotate. The hole in the lobe is a tapped thread.

When I look in the stock hole closest to the muzzle there are no marks on the barrel. In the hole closest to the receiver there is some marring. I can also see two numbers stamped in the barrel. These numbers are on bottom of barrel,  opposite of the rear sight Just as described for a Pope barrel. The wood shoulders around the holes are sharp with zero wear or compression marks as if from insertion wear.

The bolt is a CF. The bore is off center at the 12-o-clock position. The firing pin hits at the 6PM mark.
there is an interesting post on another forum I searched out. I copied one comment on it. Also listing a link if you want to look at it.   (You need to Login
One additional note. There are actually three variations on 22 cal Krags. Besides the arsenal produced Gallery Practice rifles (with the two variations-arsenal produced complete rifles and barreled receiver variations) there are the Stevens-Pope guns and a few Springfield produced (?) 22 cal rifles with characteristics similar to the S-P guns. These will not have the carrier style receivers, but barrels with the offset at 12 o'clock using the standard extractor to remove spent cases as does the S-P guns.

What is an S-P gun? My rifle does use the standard extractor to remove the shell casing.
I did check the SN on oldguns.net and it reflects production date of 1901 that matches the stock cartouche.

I will post pics tomorrow showing a couple of details. All feedback is gratefully welcomed. Thanks for your knowledge.
Tim