UPDATE!
It took a long search, a bit of cash, and one lost package, but I finally found the missing piece for my 1016. Can you see it?
Can you see it now?
Yes, I finally found a genuine domed Tropic 22 for my Explorer! As much as I love the shiny beveled edge of newer crystals on, say, a 6263 Daytona, I believe the dome better suits the character of the 1016. Plus, it's period-correct for 1969.
Sadly, I was never able to find a suitable, aftermarket, domed T22, though I came very close with one from AF Switzerland. (The fit was perfect, but the optics were off. It made the dial look as if it were surrounded by a thick black gasket.) However, I have heard about some resourceful types out there who've been grinding the edges off Clark T22s, so there may still be hope for dome lovers.