PM me your email address and I'll send you a PDF of the Ifor Williams application list which gives dimensions for all different types of tops. I've checked on ther web site and they don't seem to supply them any more and therefore can't give you a link. The list is from 2008 but obviously still of some use in cross checking.
Iv not long sold an entire s3 109 pick up tub, roof and van sides
The 110 is longer and wider, eBay or the series club would be your best bet
I can’t honestly say the last time I saw one on a 109 was. I had one on my 110 and was great as the cab warmed up quickly in winter compared to a hard top
Related...I believe...(perhaps in that "parallel universe") I have a genuine Landy aluminium roof. Bought it for a project that won't now happen...anyone interested?
DailyMike.