Unfortunately unlike the original vents which came with bosses to feed screws or bolts into, these SSV vents are really thin and wouldnt allow for screws to be put into 'em without going right through them.
The website does list them as $120 but when I went to pick them up from the post office I was suprisingly delighted. Apparently $90 is trade price whereas $120 is retail price. Miight have to get a second hand bonnet and trial fit them on. I'm doing an engineeering/design course and we do models and stuff quite frequently so I made the templates myself without ant hassles. Thanks again guys.