Mike, I don't know those models in person because I build 1/72, but, I do have a suggestion for you.
Since you are saying almost the same as I said to myself when I turned 55, two years ago, I think you could benefit from the same idea.
Think about calling "today" the start of the "later" that you were "saving these kits for",,,,,,,,and don't waste your time on any low quality kits for practice. If you do everything right, and fight your way through a bad kit, and get the paint and decals and clearcoats perfect,,,,,,,you will have a good finish on a bad model. Since you have so many good models there,,,,,,,just dive in and treat yourself to building them.
Don't worry about "ruining" a good kit,,,,,,,just enjoy building them, you already paid for the privilege. The worst that can happen is a bad seam, or bad paint job on a good kit,,,,,,but, you will still be having fun instead of "suffering through" and "overcoming obstacles"
I know this is different than what people usually say,,,,,,but, most of the time the person asking doesn't have the stash you have, so they have to buy a kit to learn and practice with. You are already past that point.
Rex