did a bit of checking and the
956 was easton "varilite" 7005 , 856 easton 7005
955 was alcoa 7005 , 855 alcoa 7005
954 , 854 754 , 554 was alcoa 7005 , all lower tange infinity cromoly
953 , 853 ,753 all alcoa 7005 , all lower tange infinity cromoly
as said above proflex didn't seem to use groups , just threw odd components at frames , then there was their own branded stuff that would appear on frames
also you had the 956 le , attack , attack le , aimal , beast , then throw into the mix that they had cromoly , alloy and carbon swingarms !
so first number deffo quality , line up in the range
second number , any ones guess
third number deffo year of sale