Well it is a PGP the line is just a CA line for a on gun tank (note the hose clampish tank rings) with a Crossman stock. The tool belt is mil surplus and the pouches were for 10 round tubes. It does look as if it has a hack direct feed. Pics of the other side and larger would help a lot.
I would say about 80.00 +/- and a couple of points for old school cool mods!