Had the '38 SS out for a little drive last night. This morning noticed a hole in the roof, right hand side above the B post. I guess there was plastic body filler in there which popped off.
Investigating, there was something inside there.
Reaching in under the headlining, I could move it around. Managed to get it out.
Thin hex nut filled with Bondo.
Cleaned it out, trying to identify the thread.
Too large for 3/8-20 BSF or 3/8-18 UNC but too small for 7/16. Not M10x1.50 too small, nor M12x1.50 too large, though the pitch seems right. Might be 11mm x 1.50 which is in Machinery’s Handbook but not in French or German thread lists. Who would use 11mm?
The hole is 15/32" or 12mm, drilled through the inner brace of the B post.
So what was on the roof?