No sarcasm. The 4 cylinder TR's and the Ferguson TE20 tractors both used the same basic engine, based on the Standard Vanguard. Different tuning, carbs, compression, etc., but any TR3/TR4 owner would recognize the Fergie engine.
To me, the clip didn't sound like a lumpy cam, as it didn't clear up much once he got some revs in, and it didn't seem to 'come on the cam', as you would expect. Given the poor sound quality of a typical camcorder played through the exquisite plastic speakers here at work /ubbthreads/images/graemlins/grin.gif its hard to know for sure. Still, if it was my car, I'd be digging out the compression guage.
Webb, an engine with a miss isn't firing regularly on all cylinders. This can be due to ignition problems or compression problems. The engine note will sound uneven or slightly rough. How rough will depend on whether it is one cylinder consistently misfiring, one cylinder irregularly misfiring or all cylinders irregularly misfiring. The discussion about cams is due to the fact that cams optimized for high rpms, don't allow the valves to seal the cylinders up for the "bang" part of the suck, squish, bang, blow 4 cycle motor, which give rough low rpm running. These cams (called high overlap cams) allow the intake and exhaust valve timing to overlap, relying on gas velocity to complete the filling during compression. Works at high rpm, not so well at low rpm. Hence the fascination with variable valve timing in modern performance motors.