Rick, similar situation for me on my Franklin. After working on the nut end with one bolt I decided to work the top, carriage side on the next. I made a small pilot hole on the top of the bolt head and then drilled with a larger diameter bit. When I got close to the bottom of the head the head popped off. I was then able to drive the remainder of the bolt through with a couple slight taps. It worked much easier drilling the top and left no scars. My attempt on the nut side did not fair as well.
Replacement bolts, new, were easy to come by in chrome but the Franklin was nickel in finish. Thus far nobody has noticed the almost invisible difference between the chrome and nickel but should it ever get to bother me I learned that the plating shop can easily dip the bolts and remove the chrome top layer leaving the nickel layer underneath as a perfect finish.

Where Are You From? Brighton MI

Do You own a car built by Durant? Proudly

Goal Achieved!
A friend recommended a machine shop that was able to remove the nut and save the bolt. :-)

Where Are You From? Fremont, CA

Do You own a car built by Durant? 2 of them