On the top frame there's a couple strips on the bows that the top tacks/staples into. What is that material? Are reproductions available for it or is it a common replaceable item when replacing a top? thx.

It was originally cardboard. It is not very usable any more, in most cases. The reproduction material is plastic. You can not see it when installed anyways. The plastic works fine. The most difficult part is attaching the plastic into the metal. I used very small screws and countersunk them. The cardboard was originally stapled in. Hope this helps.

You can get reproduction tack strips from Convertible Service: http://www.convertibleparts.com/

It's been over 15 years, but I recall using pop-rivets and epoxy to attach it. (necessity is the mother of invention) The fabric is under a fair amount of tension there as well as in the back when the top is up - you want to make sure that sucker is not going anywhere.