Soldering the pushrods is not a big deal.

"roughen" the metal pushrod with fine sandpaper. Do the same with the clevis if possible.

Mark the location of the clevis ( measure twice !!! ).

Put the pushrod on a holder of some sort that will keep the clevis in the proper position.... put the clevis in place and assuming you are using pre-fluxed solder, have at it.

Otherwise dip the clevis in flux, put in place and solder away.

Get the clevis and rod hot... Apply a bit of solder to the tip to wet the iron as you heat the clevis and rod... the wicking action of the solder will help distribute the heat on the metal.

Keep heating until you get the solder to melt when directly applied to the clevis or rod... at that point apply solder more liberally until it flows into the juncture.

Remove the iron and allow to cool.

You should end up with a strong solder joint.