Originally Posted by Retro Grouch

My general philosophy is, if I already own parts, I'll bolt up most anything and see if I can make it work to my satisfaction. You're operating with the added benefit of a friction front shifter. That'll overcome a lot of front derailleur issues. If it was my bike I'd bolt that Suntour derailleur up and see what happens. My bet is you'll have no issues at all. Back before index shifting we didn't have specific cage designs for double or triple front derailleurs.