Step on me if I'm wrong, but did not Poland make Rifles AND Carbines (short rifles) BOTH? (Shootin' Arns wif 23- and 29-inch Bar'ls both) And they adopted them both in '29, too.
Up until then, they had been transferring everything to Radom, setting it up and refurbing all the German War One stuff they had been given.
They did get the tooling from the Prussian State Arsenal at Danzig and it was certainly tooled to build the Kar98aZ: they built mine in 1914.
What OTHER tooling Poland got, I have no idea, but it certainly would have been enough to build a Rifle as well as a (comparative) Shorty.
Spandau, Erfurt and Amberg all were stripped, and there must have been ACRES of tooling just at DWM - Berlin alone. SOME must have ended up in Poland.