Hi,
  I recently acquired an original Hartmann Delta Queen with this beautiful drive mechanisim..Any idea who manufactured it? Thanks for looking!

 

Nice pick up. I'd say it was built by a previous owner, who's done a nice job of it. My understanding was that was sold either as a plan, a hull and plan or the Saito kit with steam engine. The paddle wheel doesn't look to be the Saito one so I'd say it's a home made version. The plans/fiberglass hull version measures at 60" long with a 13.7" beam not a small model.
I had visions of building the Delta Queen one day but being realistic it's not going to happen so if you're after a set of plans for your build I've recently put mine up for sale on eBay. https://www.ebay.com.au/itm/185240641200 

Hi,
  Thanks for your post. I would buy the set,
But the Queen came with both the Harlan and Greene and the
Hartman set. I wish I could find more info on the drive. It looks professionally done by a master machinist..

Just to let you all know the plans have sold.