Without knowing the details it is difficult to comment usefully but here goes.
First I would not be looking to set up a SMSF at age 75 anyway. Given the asset rich cash poor status the benefits would seem marginal.
Assets of $3M would be more than enough to see them out, assuming they are not tied up in their own home.
Seek a creative way of generating an income stream from the assets that keeps tax low and allows drawing a pension or part pension.
Seek advice from a trustworthy person if there are any around. Plenty of advisors would look at your parents as ripe for plucking.
Good luck
