Inventor prototypes?

[butlersrangers]

In September 2021, Rock Island Auctions sold a Parkhurst - Zalinski 'prototype' rifle, serial number 123792, for $8,625.
This is an extremely rare bird.
There are two known rifles of this type. These privately made prototype rifles lack the 'Parkhurst Clip-Loading' Guide.
They do have a Krag 'loaded-chamber indicator' and 'magazine cartridge-counting' device, Co-Invented by E. G. Parkhurst and U.S.Army Captain-retired, Zalinsky.

'Parkhurst Device' rifles were desired, but standard Krags were apparently obtained through 'contacts' and adapted with the Parkhurst-Zalinski 'loaded chamber and magazine contents' innovations.
Parkhurst played a role in developing the cartridge detecting devices. He and Zalinski had hopes of selling the Clip-Loading and Cartridge Counting devices to the U.S. Navy.
Parkhurst's death is mentioned in Zalinski's letters to his friend and Navy contact, Admiral Charles O'Neil.

Col. William S. Brophy published Zalinski's correspondence to the Admiral, in "The Krag Rifle".
Brophy also pictured the Parkhurst-Zalinski prototype (altered Krag) rifle, number 219208 - (if I read the picture correctly), in "The Krag Rifle". Brophy wrote that at least two examples of the prototype were known.

Since the 'Rock Island Auction' Krag, serial number 123792, appears to be stamped "No. 3" on the stock (in front of the trigger-guard), it is likely at least three prototypes were made.

FWIW - It appears to me, Brophy's photos show a Parkhurst-Zalenski prototype rifle with a serial number of 219208. Also, it appears "No. 1" is stamped on the stock, in front of the trigger-guard.

Is there a Parkhurst-Zalenski prototype rifle No. 2? ... and maybe others?
Does a prototype exist that combines the Cartridge Counter/Indicator features with the Parkhurst Clip-Loading Guide?

[butlersrangers]

Italian walnut grain and stock marking of Rock Island Auction Company's featured Krag, (Parkhurst - Zalinski prototype), serial #123792.
"No. 3" appears to be stamped on the wood in front of the trigger-guard.

The prototype Krag (serial number 219208) that is pictured in Brophy's book, "The Krag Rifle", has all the Parkhurst - Zalinski markings and what appears to be No. 1,
stamped on the wood in front of the trigger-guard.