Hi, welcome to the forum!
A few comments/thoughts..
The 102 is a gear drive, 127 would be a hydro. A hydro is better suited for some attachments where slower ground speed is needed (tiller, snow blower), unless you have a creeper in the gear drive.
They are both "narrow frames", but the 127 would be 2 series "newer" than the 102 and would have the "quick attach" system on the front. Many attachments can be utilized on either cadet with minimal adjustments.
Fyi, the 12 HP engine in the 127 will bolt in the 102 (essentially making it a 122 :wink: ). But, this doesn't sound like a good idea with the 102 sitting out in the weather for 4 years.
I find the gear drives simpler to work on, but that's what I like and am use to, so probably biased. There isn't really much to either, so don't think there's going to be any issues that cannot be worked through.
Good luck with your decision,