Awesome work, would love to do the same!
Have you considered the wheel spacing to suit the drive rods in the tgauge shop? I believe its 5.25mm centres.http://www.tgauge.com/product/327/0/valve-gear/9f01f86564ee58806bf5df7210b882bd
How do you plan to pick up power? I was considering a permanently wired connection from standard eishindo bogies on the tender.
Love the work, look forward to seeing it progress.