Recently purchased a Hunter Elite. Is it a 220, 440, 880, 890 Magnum 2000, magnum 3000 or a 1250??? Trying to grease the spring and figure out how to get the end cap off to get it into the compressor. Is the cap held on by the screw that holds the trigger casement? Got a GRT today and wanted to grease the spring while I have it down. Thanks. Lee