Thanks guys. BTW - the scale is different in the two graphs. Top one is 160 ms, bottom is 35 ms. Dwell does increase from 4ms (top) to 6ms (bottom). I'll have to go back and recalculate my ignition timing.
1993 245 Classic
1992 245+T (DD) Build thread here.
1972 P1800E Chassis number 39412 (Doesn't exist according to Volvo)