Repair/Replace the Spa ?

[NoCal NoBoat]

I'd appreciate any advice. I know there's many contractors, tradesmen, real estate, and pool/spa owners on this forum.
Moved into mom's house about 18 months ago. Last weekend, I opened up and cleaned out the above ground spa. 15+ years old. The top of the skirt structure (under some vinyl tile trim) is badly dry-rotted on one side of the octogon acrylic tub. Opposite topsides look o/k, and all of the siding is still good. The spa guts have probably seen better days, but some have been replaced in the past. Pro electrician checked the 220v. Everything is good and to code.
Pool/spa tech is much improved from the late '80s, and I'd probably be inclined to say "replace", but mom's boyfriend (a pro carpenter) built a redwood deck around three sides of the spa frame, plus a wraparound bench with hinged access to the control panel. Nicely done, needs a cleaning/brightening, but all solid redwood and wood screws and built to last.
Fix the dry-rot and replumb what I've got, or measure for a new one, and try to make it fit in the old box? No pun intended, HBers...
Thanks in advance for any ideas !

[ThongMagnet]

Go shopping. If you find one you like...and it fits, get a new one.
I went through the same thing. I spent about $300 in parts, to rebuild the pump and replace the heater element. It still looked like and old spa and did not have all the nice new features (neck jets, auto-level...etc).
You'll enjoy that new spa.

[cc322]

Buy New we just bought a new one Jacuzzi J365 and love it when were not at the river we be drinking in the spa.