LONDON — Leo Gregory, Dexter Fletcher and Tony Denham are among of host of actors to sign on for cameos in British comedy “The Hooligan Factory.”The film, helmed by Nick Nevern and scripted by Nevern and Michael Lindley, is a spoof of soccer hooligan films like “Green Street,” in which Gregory starred, and “The Football Factory,” which starred Denham. Many of the cameos, which also include reformed hooligan Cass Pennant, will be kept under wraps as a surprise for movie-goers. Jason Maza, Tom Burke and Josef Altin will lead the main cast, which has started lensing in London and at 3 Mills and Elstree Sudios. Maza produces alongside Will Clarke, Andy Mayson and Mike Runagall for Altitude Film Entertainment. The Fyzz Factory is co-financing, while Think Big Prods. and Marshall Leviten are co-producing.