Mounting 08/09 Dukes on 05/06 Prophet 100s

[asianguy63]

so i have utilized the search function and only a couple posts really touch on this at all...so here it is

i have a pair of 05/06 Prophet 100s in 179cm that are currently mounted at what appears to be true center (or maybe -1) with Reactor10s. From what i've heard, there's "dimples" but no specific markings to indicate boot and ski center marks on this model (brown color with line crest) to begin with but I'm looking to remount them with small Dukes to use as my everyday EC setup. So should i be on boot center? or +1 maybe? is there a proven way to determine where boot center even is on these skis? and moreover how does that translate to a duke-specific mount?

thanks in advance~
btw 5'7 x 155lb