Looks like a Stevens No 14 1/2 Little Scout with a store brand name.
Here is one like yours for sale. Other pictures have a plain knob takedown screw and a different breechblock contour.
https://www.gunsinternational.com/gu...n_id=101272228
Numrich lists the firing pin but I don't know if there are two different firing pins for the different shape breechblocks.
https://www.gunpartscorp.com/gun-man...2-little-scout
Jack First is out of stock on firing pins but notes "may have to be shortened from the rear." which might be the breechblock shape effect.
Frank DeHaas said it may be chambered for .22 LR but is not strong enough for any current ammo but .22 Short standard velocity. Or CB caps.