Did a search, could not find a post like this, but I'm sure I'm not the first one to think of this. Actually I'm probably the last person to think of this.
Nikkor 50mm f/1.8 G on a Nikon FG body.
Note the strip of gaff tape in this first pic. This holds the lens and the aperture indexing ring together.
Now note the location of the aperture index tab: right about where F22 would be with a lens mounted that had an aperture ring. (like the 50mm AI-S I used to double check this...)
Put the camera in P mode and bang...meter works perfectly. (in P mode, the meter will only work with the camera set to it's smallest aperture)
The trick is when mounting the lens, line up the dots and insert the lens, then tape the ring and lens together *before* rotating it to lock it. This will line up the tab about where it needs to go.
I'll post some test shots some other time once I get this camera all tidied up. (just picked it up and sent a test roll to the lab, might need the seals re-done)