edit to add a couple of pictures taken from the Internet. NOTE: 1st Gen. trigger group. The torsion spring was not on the first 100 sold with "match" triggers, otherwise the rest of the 1st gen however the second generation are somewhat different but no mechanical difference as far as working on it. With very slight effort the marauder trigger can be used in competition to good effect.
and crosman's marauder trigger next to a MK4 trigger group, almost like they say a facetalk pic and said ya that'll work.
I got rid of the spring and replaced it with a spacer ( item 6J). No need for the spring I didn't think. Others will like a different feel and slightly heavier trigger