On the topic of fibreglass wings, I just called Sid Watson to enquire as to costs. £900 a pair for fronts, £380 for rears, another £40 to have them coloured (although they will still need to be painted).
So not such a cheap option, although still a deal less than alloy and their durability is much better.
I have always been a bit anti fibreglass, but whenever I've seen them on a Morgan I've been impressed by the quality - and of course they are probably a great deal easier for an amateur like me to fit.