Originally Posted by
long john
What I ment was the holes for the pedals are blind not through holes. I thought that might held date the crank.
It's quite old if the pedal holes do not go all the way through. It is not the same as a modern 1690. The 5-pin cranks were made for French pedals and for English-threaded pedals. I recall mine (it's installed, don't want to dismantle the bike) has some inscription on the crank arm, inner face, around the square spindle hole. Is anything printed there on yours?
The two threadings are close enough that you don't want to mix them. It might work, and it might instead destroy your crank threading.