Thanks Kev, the induction trumpets supplied with these Webers are 50mm tall/ 38mm dia measured at the base. So should fit. Not sure what the optimum air gap between the trumpet mouths and the filter 'lid' steel pressing is, but I remember a Fulvia airbox with missing baffle was very unhappy at partial throttle openings.
I would also like to know more about the triple throat Solex 3b type pictured in my Solex tuning book and elsewhere. Sometimes reviews are unfavourable , perhaps unfairly.
Of course, although these are fixed jet carburettors, albeit with volume control adjustments x6, I have already received comments about 'in tune' and 'out of tune' and associated difficulties from the same experts who have in their repertoire of remedies, 'tow starting followed by the high speed thrash'.
Soldered brass floats within, so will continue with low/nil ethonol Esso petrol from Maidstone area. There was a comment posted earlier within this forum thread which mentioned camshaft /carburettors mismatch, but no further information posted since. Would obviously be useful to know more about this unsuitability from anyone who knows more.
Richard