I am just today going through the same thing. I have Nylon 8 ply 700 X 17 Monarch on it now that are close to original on the 1 ton panel. Do you think a 6 ply would be ok I found some Lester's 700 X 17 that were "reasonable " here

http://www.lucasclassictires.com/17-700x17-Lester-BW-70811L.htm
They also have a 750 X 17LT STA that is more "reasonable" here ;

http://www.lucasclassictires.com/17-750x17LT-STA-Super-Transport-8PR-624P.html

4 tires / tubes and flaps w/shipping was $1,142.00

However when I talk to Vince on the 800 number he was very vague on product info and they have the tubes you need conveniently located on the same page but it was the wrong one
Has anyone here dealt with Lucas ?
Dan