Hi Jason.
What a lovely engine! I started playing with vintage engines over 40 years ago, it never ceases to amaze me that something new can appear.
I can assure you that the R.L.E. wasn't based upon that one but from the Leek number 3 atmospheric that I bought for my son at the Angelsey steam rally in the early eighties.
The horizontal ignition tube is unusual but I'm pretty sure Stuart Turner did one with a rather nice looking
" bottle " shaped chimney?
Cheers Graham.