Interlocking rings - side by side

Hello all - long time lurker, rare poster - I’m having some design
trouble with a project and thought, where better to turn for advice?
I’m working on a set of four rings that will interlock to form a set
of silver “brass knuckles.” I want the rings to be wearable on their
own, and, given that it’ll need a fair amount of heft to bridge the
space between fingers (and make room for a locking mechanism), the
least bulky they can be. I don’t yet have pictures, I’m still
working on the basic shapes in wax. My question is, does anyone have
any ideas as to how to link them together in the least obtrusive
manner possible? I was thinking standard puzzle tongue and negative
space type thing - put in between the fingers horizontally rather
than vertically, if that makes sense - but it occurs to me that a
vertical system might be more elegant, and less obtrusive when
they’re worn alone. My biggest fear is getting almost to the end and
realizing that I messed up the mechanism and have to start all over.
I’ve done some wax work, but nothing interlocking, nothing requiring
this kind of precision. Orchidland, I throw myself upon your
mercies!

Help?!
Bekka in Boston