Hi Guy,
Forgive the imprecision of my comments re. the beading, but if you refer to the picture in that link (post #338), you will see that these strips were on either side of the passenger doors (all except driver's doors). There was also a horizontal strip on the bottom edge of the cab sides. I am not sure if this strip extended all along the bottom edge the body sides between doors on 4 TCs - as with the 4 CIGs.
There is also an excellent thread by Brian Daniels which has photos of his very fine build of a 4 TC in 7mm. These features can easily be seen here (post #2693): http://www.rmweb.co.uk/community/index.php?/topic/1458-brians-7mm-diesel-workbench-4tc-conversion/page-108
Some have insisted that the door panels were flush with the beads on these vehicles (and 4CIGs, 4 REPS) therefore, the doors being slightly proud of the body side panels. Looking at the photographic evidence, I am not convinced, but could be wrong.
All the best,
Colin