Found during oil change

[ICCARS]

I'm sorry to say that I believe that you will still have the original problem present, as push rods do not bend from valve stem seals and they do not cause valve stem seal retainer springs to break (not that I believe for one minute the photo you posted is of a broken valve stem seal spring). Sorry to be so direct but I think you might have been given the run around, as if we do the math we can deduce that the bent pushrod was a direct result of the valve train locking somewhere for a split second, hence the broken damper spring piece you found, and hence the issue still remains if this spring is not found and replaced.
As for having varying pushrod lengths within your engine I would be pointing the finger at the engine builder as they have no idea IMHO on how to set up an engine, hopefully the mechanic you used to rectify this checked the full pivot fulcrum of your rocker to ensure proper positioning on the valve stem, so as to not induce any side load on the valve guides..
Just my two cents worth, but I would not be giving the engine curry any time soon.