I've got a 19" Explosif frame that's a bit of a mystery. It has all the characteristics of a '90 frame, such as 1"headset and rear brake noodle, but it has 1991 solid colour paint and decals. The paint and decals look original to me, but I suppose it could've been repainted. Someone else has suggested it could be a mid year crossover model. Either way, it's ripe for a repaint in the correct 1990 splatter colour scheme, https://www.retrobike.co.uk/threads/18-1990-kona-explosif-frameset.462413/
Thanks for the reply, I'm after an original splatter model, as I don't have the skills or knowledge to get it redone. Also an 18 is the largest frame I can manage as i'm only of a medium height.