I think that -- on balance -- the alert put out by the Forest Service was fair. In fact, considering the point made by Mark above, maybe it didn't go far enough. I would also require either type currency or, at a minimum, proficiency with fuel management if it's a pre-73 Skymaster.
Fuel management on these aircraft with separate auxiliary tanks is anything but trivial. I have a lenghty page on this subject in my "backup" Skymaster website at
www.SkymasterUS.com with a quiz at the end. I'd bet that less than half of the pilots flying these aircraft would get all the questions right.
Ernie