Need some help identifying this rifle. It's a gew 98 no other markings except on 22 bolt #48. Top of receiver where the numbers should be have been filled in and reworked looks like factory rework. Still has 8mm receiver but has a 22 receiver inserted into stock receiver. Has 22 cal sleeve inserted in barrel. This is a single shot top load.I do not think it's an erma. Front sight is standard 98 blade, rear sight while adjustable the top looks like a kids play ground slide. Anyone seen a rifle like this. Nothing on google