Terry probably right
i'd say 1981 or maybe even later as 'these' pedals were (still) being advertised/sold as MP-1000s in 1981 (with 'bmx' on cage instead of xc compe; the Compe supposedly the mtb version of the mp1000)
read Just..Me..Chillin' s posts on page 2 here (or kdw712's and ROSBMX's posts on page 1)
->
http://bmxsociety.com/topic/13792-suntour-xc-ii-help-required/page__st__20's=18f1ce2feb969dff8fda91b0858067fc_____________
But then again Chris
might be right with earlier/ 1980, as Just..Me..Chillin' states the MP100s "were spun off from the early MTB version called the XCcompe".
So if Just..Me..Chillin' is right then XC Compe SHOULD be older than the "bmx" = mp1000s (which were (still) advertised/sold in 1981).
(This again would mean that the timeline Terry posted is incorrect)
No proof, just confusion