the grips should fit. if you put the e-frame on it, to take off the old frame there should be 2 screws on the frame holding it on. take those off and take off the bottom line asa from the frame, and swap them out. the feedneck won't work, because the mr1 has a powerfeed. clamping feednecks and such are ment for vertical feed guns. you're pretty much stuck with using the elbow and hopper unless you go with a qloader (which is somewhat expensive) what he did recomend this though
http://www.pbreview.com/products/reviews/4843/
it's an aluminum replacement for the feed it has, and converts it to a vertical feed. he also recommended using the ccm ion threaded heli clamp no rise feedneck
http://www.pbreview.com/products/reviews/4757/