Farmageddon 2009/2010

I used my new N.A.G. H1 1978 in 2009/2010 at a local scare attraction (Farmer Ted/Farmageddon) Nr Ormskirk ,England (See pic) for 2 x 31 night runs, wearing my mask for a minimum of 6-7 hrs per night.This was aside of multiple training hours.
Mask is still in very good shape, except forehead area,which has in one area began to collapse.Any ideas on how to strengthen would be appreciated.

Exthreesome (Richard)