Yes, RWHC - I was also referring to the underneath exposed floor of the A-Frame as every now and then a new owner says they want to do the same thing you have described (spray or seal it).
Congrats to your new purchase.
2012 FR Flagstaff T12SDTH
1996 Shadowcruiser Pop Up Truck Camper
1967 Newell Motorcoach
2003 Ford F150 5.4 V8 Triton Super Cab
2004 Nissan Titan LE 5.6 V8 4x4 Crew Cab