I can't remember if that one was "Fast Flight Compatible". Might contact Martin and find out for sure. If it is, I see no reason not to use a "FF" type string on it--just make sure it's built properly. If not, I'd stick with dacron.
With carbon arrows, just be sure the over-all arrow weight is high enough. I like to stay with at least 9 grains of arrow weight per lb of draw weight (9 gpp). It's quieter and less shock that way also.
He's right on all accounts. I dodn't think Martin's back then had limb tips to support FF strings - so I'd call Martin with your serial # just to be sure and ask them. Use a FF string on a bow that doens't have strong enuff limb tips and you risk blowing the tips right off! I've seen it happen!
I shoot a 1971 Bear Kodiak Hunter that is in mint condtion - B50 string with 5/16" Easton carbon arrows, 9.1 grains per inch....and they shoot great for me (of course shooting 5 in feathers on them). The carbon's are nice and straight, easy to maintain - much easier then when I shot both alum and my own homemade wood arrows. I found my alum 2016's and 2018's off the recurve getting bend too easily! Doesn't happen now with my carbons!
Break that trad bow out and start shooting! Shooting trad bows is on the rise again! It's plain just 'more fun' to shoot them!
: )