You might be heading closer to 80#
You should hang in here until you hear from the experienced R/D builders on stack.
Go ahead and build your form to 1.5". That's about as narrow as you will find in stock width. Ordering special widths will not be a savings and the glass might not be available at all.
Also, It can be difficult to get a full 1" blank off a 1" form. There is always some little squiggle that costs a bit of your width and at 1" there is nothing to spare! With a full 1.5" to work with you will hit your dimensions without any problem.
I build one design that is and must be a full 1.5" at the fades. I finally arrived at using a 1.75" form and stock (based on suggestions made here).