Steve,
You usually find it on the side(s) of one or the other of the hooks, and maybe at the rear surface.This is usually very minor and is only a product of the tight fit of the hooks to the plate.The importance is only that they should be scraped off,so the ring fits flat onto the plate before boresighting with the adjustable block.With regard to the lazer bore sighter, I'm sure it will work.The procedures I described were thought out a long time before lazer bore sighters were invented.I wouldn't be surprised, at all,to walk into a shop and find them using one now.To boresight the traditional way, you have to have a vise located so you can see through a window or open door(Fred sighted on a transformer,down the street from the shop).With a lazer sighter, I guess the vise location wouldn't matter.
Mike
