Old thread, but thought I'd add what I can:
from what I can tell, there aren't many people modelling SP narrow gauge stuff. As Si mentioned, I have been modelling it for the last few years but haven't been posting online for some time. Between losing all the photographs to the Photobucket scam and being busy with other projects that tend to take over the garage, I haven't been too active in modelling but am hoping to get back into it at some point.
Would love to see others modelling and posting SP narrow gauge stuff though!
The tumblweeds are made of synthetic pillow filler material lightly sprayed with flat spray paint then gently rolled in the palm of your hand like a prized booger...sorry for the graphic description, but that's the best way I can describe it. The ones in the pic with the old Model A truck are earlier versions, later ones I used less color and they looked better.
I can't remember what magazine it was, but someone did a really nice conversion of a Bachmann On30 4-6-0 into a SP NG one. Wish I could recall which magazine that was, likely it was the NG and Shortline gazette...