Marginal.
Measuring it up, there's a 1/4 inch spare at the point where the top of the bonnet side panel meets the servo - and that's not at the widest part of the servo...
You'd have to notch the side panel for it to fit - at both of the stepped sections of the servo. I don't know how much longer it is, but in my situation if it got any longer I may have an issue with my braided lines.
Here's a link to some chrome 7" servos on eBay:
http://www.ebay.co.uk/itm/Zinc-Power...#ht_924wt_1195
They're £30 quid more than Dukesville... And it looks as if the vac inlet is in a slightly different place.