I revived a PV from sitting in a shed for about 15 years.

1) Brakes - replace everything except the hard lines - and give them a VERY pessimistic looking over. Replace or rebuild all wheel cylinders and the master cylinder, replace all 3 flex lines. No room for iffy components on a single circuit system.

2) Flush the gas tank well - or stock up on fuel filters (installed prior to the fuel pump) and replace as needed for the next year or so. Replace all rubber fuel lines.

3) Mechanical fuel pumps are not happy with being left sitting for that long - if it won't start be suspicious of it not working.