All depends how long you plan on keeping it and what your budget is. A full underside resto done right will cost thousands.My 8 has been mostly in storage the last 6 years but I'm now spending more time and money on it.
The biggest question I have is should I strip it back completely and do a full restore, cleaning and sealing the entire chassis. Replacing bushings, arms and such like on the rebuild and if so what ball park figure would I be looking at.
Or is it wiser to spend time and money dealing with the most critical areas where some rust is appearing and not worrying so much about areas less prone or still fine today?
However, if it’s a keeper and you can afford it, then why not.