It's not "kettling" as I would expect a reed valve engine would. It sounds flat and unstable at idle, and to me that points to an air leak. Also looks like the idle speed screw is turned way in, which would also be something you'd do to compensate for a non-carburetor related problem. Turning the air screw in will richen it up, and should allow it to start "kettling" but if you turn that screw all the way in with little effect I'm thinking air leak. Need to read over the leak check threads scattered throughout the forum, there are many detailed methods and setups used by forum members. It's not hard to do, just need to collect the required pieces & be diligent sealing off the exhaust/intake, and limit your pressure to 6-7 PSI max.

Could also be retarded timing as well, but, I'm betting on an air leak. 

 

I think you are on to something. 
I'll dig in. 
 

I see leak down test kits from 100 on down.
I'm kind of a miser. Would this one work okay?
www.harborfreight.com/cylinder-leak-down-tester-62595.html

Harbor Freight wants you to start from scratch when you visit their website...searching I see the Maddox or Pittsburgh ones. Probably either will work and you'll need a couple of expandable freeze plugs for the intake/exhaust. Then some soapy water in a spray nozzle of windex and then when at PSI spray away. 

 Going back to the baffle pic. I said it looks like it must originally have been welded to the tail piece you show there. BUT that wouldn't work a there no way for the gas to get out down the tail pipe. So maybe the spot welds that held it deep down in the end 'did' let go or someone knocked it free then dropped it back in loosely. I dunno--parts shows it as one piece. Ok just looking again at Partzilla i see that bit is shaped so gas can get past & out the back, but didn't think yours looked like 'that' & just a round pipe so no way to pass gas out the back if welded on.

 

Yeah it's weird that's how it came out. The little piece was laying loose.

it doesn't make a difference in how it runs though. On or off, it idles (rough) and hesitates when getting gas.. lots of sputter and no power... 

The 71 DT1 E baffle had the spark arrestor as an integral part , as per RT's parts diagram .
The DT2 and 3 had the spark arrester welded into an internal baffle in the pipe .
Yours has obviously come adrift , and getting it back in place might be tricky without some pipe surgery .
 

It was just kinda laying in there sideways. A secondary problem for the moment I suppose

Yeah Swoop, that pic was from the "73 DT3 parts pic on Partzilla but i thought they were integral so i dunno haha. I think its come adrift on this one. I've knocked a few out going back years, knock them off the welds then shake them back out on blocked exhausts, then think hell its loud.