Hello David and welcome to the forum.
You might find it better to start a new thread rather than tacking your post on to an earlier one, things get a bit lost in all the other postings.
Can I suggest you join the National 21/2" gauge Association, very reasonable subs and an excellent little magazine, you will find much help and advice available. I used to be membership secretary and old habits die hard! There is a website with details of drawings and reprints available
There are several of these loco's in the association, I believe that reprints are available from them of the original B-L construction manual, Drawings may be available from the association or Maxitrack who now have all the Greenly drawings. For inspiration have a look at John Baguley's website he has restored several 21/2" gauge engines, I regularly pinch his clever ideas! I was also posting on this forum about restoring a 21/2" loco under "Problems with another president" ( this has stopped for a while as I decided to change lathes and have temporarily destroyed my workshop)
Good luck and keep us posted on your progress and if you have any questions I'm sure someone on the forum will have an answer.
Dave