OK, having had my money's worth out of you all on the issue of DT2 fuelling, the next issue is baffling. Exhaust baffling.

Judging by the number of dogs jumping over fences when I approach, or babies that start screaming, old fogeys who shake their heads and tut-tut, people of certain ages and dispositions who break into a smile as a ratatatat past, and the bloody racket my DT2 makes, I think I'm pretty certain it doesn't have an exhaust baffle. It. Is. Noisy.

How do i know whether it has one or not? I peer into the noisy end of the zorst and see a bracket thingy secured by externally-accessed screws top and bottom, but not much else. Are we back into rare-as-hens'-teeth territory for baffles? If they're out there, which ones fit?

Or do I just get the earplugs out that I thought I'd retired when I got rid of my Yamaha FZ with its Akrapovic can...?

You could take a look at the exploded diagram for your bike on the CMSL site.
www.cmsnl.com/yamaha-dt2-1972-1973-usa_m.../partslist/B-11.html
From your description of what you can see it sounds like it probable does have the outlet pipe fitted.
They are reasonably loud with it in and from experience of forgetting to put the retaining screw back in my RT1 and the outlet shooting out, they are VERY loud without it.

OK, yep, there's a bit missing: the piece that looks like the missile warhead part of (2) is absent.

Looks like earplugs and anti-social behaviour are on the cards.

That " warhead " is the spark arrester . At some point Yamaha changed from it being part
of the baffle , and permanently fixed it as part of the pipe . If you shine a light up into the exhaust ,
with baffle removed of course , if it's fixed in there , you'll see spiral vents .
If not , the baffle complete with spark arrester is a pretty rare item .

Adapt an underneath road pipe like i did of an RZ350 or 250. Thick walled header ^ good muffler & it worked without robbing power surprisingly & was mouse quiet with no resonating noise either through he walls. Could just about guarantee an aftermarket well made old design motocross pipe for a DT2 or RT2 would have thicker skin than the original ring dingin pipe then hang a really good spark arresting modern muffler on the end & it'll be quiet.