I have a Colt Officer's Model Target in .22. '43 vintage. Is hammer push-off a common trait for this model? I assume the single action has been lightened so much that the malady followed. Can the push-off be eliminated but still maintain the trigger pull?

I spent many years as a Colt Warranty repairman.
Push off was caused usually by 'home gunsmiths' rounding off the sharp edge on the sear portion of the trigger and/or the equally sharp notch on the hammer.
Would suggest that you have a competent pistolsmith check it for you.
It could be dangerous in as it could have the hammer fall when you did not put really adequate pressure on these undoubtedly maimed parts.
Stay safe!