Some additional information I garnered this evening which may be of interest. First, the prototype's information is here, including a basic dimensional drawing:
http://de.wikipedia.org/wiki/DR-Baureihe_64
Much more information here:
http://www.bundesbahnzeit.de/page.php?id=Baureihe 064 < Link To http://www.bundesbahnzeit....php?id=Baureihe%20064
From that and Piko's dimensional drawing here:
http://www.piko-shop.de/index.php?vw_type=artikel&vw_id=15196 < Link To http://www.piko-shop.de/i...rtikel&vw_id=15196 (see AbmaBe file in text), some scale conversions can be made.
Prototype gauge 1435mm: G version 45mm: scale 1:32
Prototype length over buffers 12500mm: G version 480mm: scale 1:26
Prototype wheelbase (leading-trailing wheels) 9000mm: G version 358: scale 1:25.1
Prototype height 4765mm: G version 170mm: scale 1:28 (*)
Prototype width ?mm: G version 105: scale ?
(*) - not measured from the same places: prototype to top of funnel; G version to top of cab
Rubber ruler applies as usual with what seems larger gaps between the main wheels and both pony trucks. To my subjective eye the loco doesn't quite have the squatness of the prototype due to the height/length scale variations, but the valve gear and main wheels are things of beauty. I also note from Piko's description on their website that this loco has a 7-pole Buhler motor and stainless steel drivers. Reads as if Piko have stepped up their offerings a notch with this loco. The valve gear seems to knock Train Line's new Mallet out of court......
There's a nice YouTube video of Piko's model in action in the link below. The loco shown appears to have running gear LEDs like the lGB Harz 2-10-2s!
http://www.youtube.com/watch?v=HyWbkhraoBk
Tempted? Oh yes!
In the meantime, here's one spotted stuffed and mounted at Frankfurt (Oder) station last April: