I can understand wanting to remove the gauges on a BJ8 to change the bulbs, but on a BT7, it's far easier to just reach under the dash and pop out the bulb holders. Removing the gauges can open up a can of worms, like O-rings being stuck to the dash/gauges (and often, both), the O-rings will almost certainly break in the process__even if they're only a few years old.
I'm sure I could come up with another handful of reasons to leave the gauges in situ and change just the bulbs...