Ferkin ell mate der want me to give you the why's and wherefores of the UK Boating Industry from the early days of Glass Fibre boats from the last Century?
In a Nutshell
Names such as Fairline, Princess,Sealine and like yours Colvic started with little uns and went bigger
Colvic made so many hull types and different levels of fit out and 'sail away' steps.
Lot's where fitted out finally by different Yards and hamatuers
Birchwood another maker who made 'small' and went bigger
The list goes on and I am not the Guru to list all or talk about all
Although a self confessed MOBO Anorak there are others o nhere that have a lot more knowledge than I do ref your question but not many are much older and most have more teeth I reckon
I like your question however
Quiz Guys
Of the aformentioned Manufacturers, who makes the smallest?
Funny thing with boats it like Sex, accordin to swmbo!