Hi guys, went to fit head today removed for to check if warped or not before doing so and 'you wont believe my luck' the small circle guide thing that goes on bolt hole to align has fallen down channel possibly water? diagonal next to bolt hole where it meant to go. I nearly managed to get it back out but it dropped and now has lost sight altogether. I removed sump hoping it had fell in here but to no avail so remvoing bottom end tomorrow to get a good look around to find it, any hints at how to find/ retrieve it or where it could be, problem after problem with this