The first "finger nail" is cut from the bottom of the seat tube with
a hack saw. I then use bastard files to rough it almost to the scribe
line, then use the rotary with a sanding drum to finish the cut.

The fit looks good.

Checking for fit and alignment prior to cleaning and fluxing.
The bottom line on the seat tube is the end of the butt. The
second line up is the end of the taper. Very short!