'polandaj' - Thanks for responding about your "1894" marked receiver. The 'notch' was done at Springfield Armory during a 'program' to update early rifles to a model 1896 configuration. This happened in 1897 and 1902, (if I recall correctly). The receivers required 'local' annealing in the area where the hold-open 'notch' was cut, so the work was done at the Armory.

IMHO -You have a nice looking representation of a model 1896 "Carbine", put in a correct carbine stock.

Your receiver, #58783, was likely once part of a rifle, assembled around March, 1897.
This serial number is not in a known range for model 1896 carbines.

Your rear-sight is a model 1896 rifle sight. The leaf is only calibrated to '18' (1,800 yards). The carbine sight is similar, but, has "C" markings on the base and leaf. The carbine leaf is calibrated to '20' (2,000 yards).

(A correct 1896 carbine rear-sight sells for over $500, by itself).

I hope you were not taken advantage of on the "carbine".