I have a super comanche I'm working on for someone. There is a hammer actioner spring and base and a cir-clip.

the spring is tough to push back to get either the cir clip or base back on.

is there a gun smith tool that will grip around the spring and give you enough leverage to push the spring down?

where I can get the cir-clip back in.

First put on some extra heavy duty eye protection. You're working with springs and you can't duck out of the way fast enough when they decide to take off..I have the scars to prove it.

I take it you need to compress a coil (main) spring onto a mainspring guide,,hold it there and insert it into the frame between the hammer and the springs base in the grip frame.

A lot like a Ruger ,,they have a small hole in the guide to place a pin thru to hold the compressed spring in place so the assembly can be handled easily. The pin is removed when the hammer is cocked back to slightly take the pressure off the pin when the assembly is in the frame.
Your gun may or may not have that feature.

One easy way to compress the mainspring on it's guide, and this sounds crude,,
but with the 'hammer actioner' (main spring guide) in a vise with the bottom end facing out,,place the mainspring on the guide.
Then take a sidecutter pliers and carefully place it between the coils of the spring just a couple coils from the end.
You are not cutting anything,,just getting a hold of the spring.

Now push and compress the spring on to the guide by pushing with the pliers. It may take a couple trys as you find the right pressure to grasp the pliers to both hold the spring and also just glide along the spring guide.
Usually a quick firm shove does it best.

If you have the pin hole mentioned above, shove/compress the spring just passed the hole and then grip the pliers tight enough to clamp it to the guide rod and hold it there. No it won't cut the guide in half. Place a pin thru the hole (a paper clip usually works well).
Release & remove the pliers,,you are done with them.

If no pin hole,,compress the spring as far as you think it's necessary for assembly. Grip and hold it there with the pliers. Don't let go of it!,,take and immedietly assemble the spring w/guide into the frame lining up the hammer and the spring guide base in the frame. When correct,,release the pliers and the spring will snap down onto the base & into place.
Hope this helps