I just noticed that the Hasselblad 903 I bought used has a reducing bushing installed in the tripod hole, lessening the mount from 3/8" to 1/4." How do I remove it?
There should be a couple of slots, one on each top edge of the bushing. I would take a slotted screwdriver that is sized, proper width, so as you can get it in and use both slots to take the bushing out.
A method I have used in the past.....take a 1/4" bolt .....put on a nut....run it up the bolt, now put a 1/4" spacer that about 1/2" long or some 1/4" washers (all available from a home diys center) thread the bolt in the bushing. While holding the bolt still, tighten the nut toward the bushing. It should tighten on the bushing without tighting the bushing any. then back the bolt out with bushing attached.