Window handle for Marvin Windows, installed in 1984; Pozzi's installed in 1990

It really depends on what you have. Some newer crank handles work fine on older operators, but it depends on the diameter of the spline and the type of operator you're working with. If you can send us pictures, we'll tell you exactly what you need. 

Thanks for the pictures. I believe this might be the 39-333 and 39-334 type dual-arm operators, with a short link arm. Look at the dimensions of the 39-333 below and compare to one of your old operators. Let me know if this matches what you need, or if anything differs. This type of operator uses the 39-114L Crank Handle and 39-107 Covers sold separately. They are coated in an electrostatic powder that is supposed to help against corrosion. Unfortunately, the rollers at the end of the straight arms are still nylon; but you may want to make sure you don't need a new track for them to run in--see if the 39-505 matches what you have. 

Thanks for the very kind words! We're always glad to help, and appreciate you spreading the word. As far as the track goes, basically if it's bent, rusty, or damaged in any way, it may be time to replace it to ensure the operator runs smoothly. Otherwise though, with these adjacent accessories to the operator, if they are not damaged there's really no need to replace them. Let us know if you ahve any other questions.