find replacement part for casement window crank

I have 35 to 40 year old DUCANA windows(Chatham Ontario Canada company)
The name TRUTH is stamped on the arm.
I need both left and right cranks.
I have found 9.5 inch and 13.5 inch and 11.5 inch cranks but the measurement as I read it is 11 inches. Center to center.
Is it just poor measuring?
Any help with part numbers would be great.
Do I need to get new handles or can I use the old ones? 12 teeth on crank shaft.
Thanks for your time and effort.