What is this gun?

[lorddan01]

Hello,

We are clearing out my late grandads house and have found 2 of these guns. They have no markings on them. All I know is they were used with the (i believe) aluminum rods shown. I'd really appreciate any info on them please. The rods have MCP embossed on them.

http://www.flickr.com/photos/101982675@N07/tags/gun/