Joe Poyer gives the most information on the model 1892 cleaning rods.

I don't know if his dimensions are correct. He describes four variations.

Poyer gives the thread as .181"X 26TPI (I think!) and the threaded area as .475" long.

He gives rod lengths as going from 29.50", later reduced to 29.25".

He gives basic rod diameter, (not including head-area), as tapering, from .20" (behind the head) to .189" (in front of threaded area at rear).

FWIW - If I was having one made, I would get a $12 front section (of the 3-section rod) from Grandpa's Gun-parts. (The head dimensions are almost identical to the last type of model 1892 rod).

I would have the front-section rod's thread turned down to a simple pin. I would have 21.25 inches of .20" diameter rod counter-bored to accept the 'pin' and have both rods silver-soldered together.

A nice inexpensive item, to go along with Jon's Krag, would be a reprint of the 1894 Ordnance Department booklet: "Description and Rules For The Management of the U.S. Magazine Rifle and Carbine Caliber .30".

These show up at gun shows and on ebay. The 1894 version shows the front and rear areas of the second type of model 1892 cleaning rod.

Although illustrated at "full size", the rod graphic may be slightly oversize and not conducive to precise measurement.

FWIW: Poyer gives thread size as .196"X26TPI.

'Ordnance Rules' illustration appears about 24TPI and about .300" length of threaded area.

Probably irrelevant, but, threaded end on three-section rods is approximately .162"X30TPI.

'olderthansome' - You had the 'good-eye'. I totally missed the drawing in the appendix, (page 212), of Brophy's - "The Krag Rifle".

It appears Joe Poyer was simply citing the dimensions given by Brophy.

FWIW - 26TPI is the pitch used on Krag side-plate and sling-swivel screws.

It would be fun to measure an original "long wiping rod" to confirm Brophy's dimensions.

p.s. Brophy also has a dimension drawing of the 1st type of brass tipped rod on page 212.

'Jon' - I am not aware of any appendage that screwed on to the threaded end of the Krag 'ramrod'.

I believe the 'manual' says it all. The treads were to retain the Rod in the Stock, via the threaded 'rod-stop', (the plate inletted into the stock).

Local Boy - That's a good comparison and stop-gap idea. I imagine that it has been done.

On the rare occasions that I have seen early Krags with cleaning-rods, at gun-shows, they have sometimes had 'brass-tipped' rods. The rods, even all steel ones, have looked 'suspect'.
For a hobbyist seeking to fill a hole, it would be a lot easier to make a substitute rod with a brass-tip, than a 'flared' steel one.

IIRC - The real Krag brass-tipped rod use was short-lived and the rods are very rare.

Out of curiosity, I measured the steel rod on my (7mm) No.5 Remington Rolling-Block rifle. The Rod was about 1 inch too short, too small in diameter, and the screw thread was cut similar to a wood-screw.

(I like your 'comparison list', but, I think the Krag thread is probably 26 TPI).

If Jon's Machinist friend can make him one to Mallory's specifications, that would be pretty cool. If he could make multiple ones, at reasonable cost, he could make several people quite happy!

A 'stop-gap' rod that is too short would look odd. The 'flared part' of the rod has a visual relationship to the Krag's muzzle area.

(I suppose an 'extension' could be added to a substitute rod that is too short. FWIW - I would prefer a 'correct' replica).

I don't have an early Krag and maybe never will, but, if ya got em ... flaunt em!