Stock 1954 Mercury - To preface, I'm just an old-time shade tree mechanic and it doesn't take too much to stump me.  The engine has been progressively running rougher (missing) for the past several hundred (700-800) miles and last week I peeked inside the distributor cap to check for cracked or broken pieces.  Oh, the engine has about 2,000 miles since rebuild.  It appears that its firing well in advance, as at each brass electrode inside of the cap (each plug wire) the flat surface surrounding the electrode on the leading edge (counter-clockwise rotation) is blown or melted away in a tight vee pattern to a depth of about 3/32".  Timing is set at 3 degrees BTDC
at 500 rpm.  Also, the rotor cap electrode firing end is black (dusty carbon) only on the leading edge instead of the middle of its face.
The points, set at .015, appear to be opening correctly.

The engines starts immediately, idles a little rough, and then begins to protest when I let the clutch out.  What gives? ? ?