I'm skeptical that this is a radiator shroud rattle, it just doesn't sound like that. But, I'll defer to the experience and age induced wisdom of the other members and pull the shroud to see if that's it.
I wouldn't say that it sounds like a couple wrenches slapping together, it's more of a clack and I might be high but I swear I can feel it in the footpegs.
I can be cruising along with no odd sounds at all and then all of the sudden, with little to no change in throttle... clack, clack, clack, clack, clack, thunk, clack and then it's gone again. And every once in awhile, it's a screech like a bearing going out.
I don't know how to describe it or what to compare it too, I've heard the sound before in other things that I've messed around with like an old kitchen mixer that had the disc which held the mixing bowl which sat on a ring of bearings to allow it to spin, you could spin it by hand too fast and it would make a "BVVVVVVVV" sound and then as it slowed, it would stop and just keep spinning. That's what it sounds like but most of the time it's just the clack.
I know it's not the paint can rattle because I can hear that on cold startup as the RPMs climb up and down right after you start it, they go up and as they come back and I can hear a "tack, tack, tack" coming from the front of the motor, this clack only happens in gear, doesn't not depend on speed of the bike, only RPM and only happens under load, it does not do it on decel in gear.
Driving me nuts...