flow control valves

I have 2 very old flow control valves on the supply side, one on each zone, (going out to the baseboard registers) of the boiler, they have been there since the original boiler of 1953. They were never replaced when current boiler was installed, and they are very crusted and I seriously doubt they work correctly anymore. (see pics)

They are propably frooze in the half open/ half closed position. From all the crust and sediment on them, they appeared to have leak at one time or another and someone before me try to tighten the screws on the top of them all the way down to stop the leaking. It appeared to work, they are not leaking. If you look close at the watts flow control pic, you will see how the screw is really bent and corroded. You could break it off with you fingers. The original boiler was replaced by this HE mini fin lochinvar boiler in 1987. (see pics)

I recently replaced both zone circulators with the taco 007-f5-IFC which are installed on the return side (coming back to boiler). Which are equipped with flow control and according to instruction sheet are supposed to do basically the same thing those separate flow control valves do. Additionally, instructions say these circulators equiped with IFC, eliminate the need for seperate flow control valves. (see pics)

Should I replace those old separate zone control valves with new ones? Or can I just remove them altogether and replace them with straight pipe now that I have the new 007-f5 with integral flow control? or should I just leave them alone and wait until they leak or I get no heat in the house? They are ancient. What would you do? What are my options?

good advice or recommendation from an experience hvac technician would be greatly appreciated. thanks in advance.

Pictures here.