An interesting thing about these old advertisements is that things could be vague and exactness was not required or necessary.
 
The graphic shows a model 1896 Krag carbine.
The text describes carbines made with "new model 1898 stocks" and new or refinished parts.
(I suppose the stocks could have been model 1898 carbine stocks, model 1899 carbine stocks, and 'cut-down' rifle stocks).

It is clear that Stokes Kirk and other companies assembled 'parts carbines'. These arms met a demand 'back in the day' and they are still with us, (sometimes causing much head scratching).