Cafe racer seat speed twin

quite fancy a cafe racer type seat on my speed twin the one I really like is the genuine triumph one it’s designed for the 25 model it will fit previous years but it doesn’t butt up to the tank properly there is at least a 15 mm gap between tank and seat which I am not to keen on. any recommendations for a similar type of seat or any suggestions how I could fill the gap with out it looking to obvious.