Obviously you have your own priorities but never in a million years would I make that trade.
I would suggest not getting rid of the Colt. But your choice. I would get rid of the Vette first.
Trading a C O L T for ria, are you smoking crack cocaine
I am fairly certain that full size slides/barrels do not fit the commanders, and vice versa, correct?
I think you answered your own question with this comment. Seems to me that you will regret it.It's a great gun, and to be honest I have a knot in my stomach just considering this idea.
If you have the 1991 3.5" compact than you have the officers model frame which is both shorter in the front and the grip length than both the full-size govt and commander. The commander has the same length grip as the government only shorter up front for the 4.25" barrel and slide. A full size slide and barrel would not work on a commander with the shorter dust cover. A popular compromise is to use officers frames and commander slides.