Try your sparkplug-attached-to-coil test this way: disconnect harness wire from negative coil terminal and connect a jumper. Key on, plug body grounded somewhere, and touch jumper to a good ground. If spark fires, coil and its voltage supply are OK.

The points in the distributor should ground out the coil negative terminal in the same way - this is what causes the coil discharge/spark. If the wire to the condenser was burnt out, you likely have a shorted condenser. This would present a constant ground to the coil = no sparks. Go to the dealer and get a set of points and new condenser. I wouldn't cheap out with aftermarket parts here - the OE stuff is high quality and will last a hell of a long time....a fraction of a penny per km.

Remove all plugs and use a socket on the crank bolt or even just pull on the accessory belts to turn the engine and get a distributor cam lobe directly under the points rubbing block. Install points and adjust gap to spec. Install new condenser and be very sure all wiring and terminals are properly installed and insulated from points plate, distributor body, etc.
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Bob (son's 81-244GL B21F, dtr's 83-244DL B23F, 'my' 94-944 B230FD; plus grocery-getter Dodge minivan, hobbycar 77 MGB, and a few old motorcycles)