Glow Worm Space Saver 50 Mk II - front cover warped?

Hi, BG changed my meter and cut off the gas supply. They couldn't relight the boiler and said it wasn't their problem. As it's in a cupboard (I think the cupboard was built around the boiler - before I moved in) I've had to take the cupboard all to pieces, and the front cover was jammed on so I yanked it off to light the pilot but now it won't fit back on and pilot keeps blowing out - repeat remove cupboard, front cover etc... BG have now quoted £4600 to replace the boiler, in a new position, with new pipes, and a new water cylinder. Surely I can just buy a new cover for the boiler? I think it's probably about 20 years old though. Any ideas?