There were some construction articles in The Miniature Locomotive, a magazine put out in the early 50's.
"A Beginner's Locomotive" by Cliff Blackstaffe?
"The Miniature Locomotive" was published every two months. I have from May-June, 1952 through November-December, 1954, which I believe was the whole run. Publishers were Richard Bagley and Robert Day.
I dug out my Miniature Locomotive magazines. The Cole's 0-4-0 isn't Cliff Blackstaffe's Beginner's Locomotive - that was 3/4" scale. There weren't any construction articles, just a description. It is only mentioned in one article - Puff'n Billy Line by Viola and Eugene Paul, on page 22 of Volume 1 Number 2, The Miniature Locomotive for July - August 1952.
I have a full set of orginal Puff'n Billy 0-4-0 1" scale full size drawings dated march 29 1952 name on darwings E.J. Paul 19 drawings in set 20"x34" great condition never used white back ground blue lines
Also have 0-4-0 3/4 scale drawings (4 sheets Blue prints)
dated 1-1-36 Charles A. Purinton same engine as Puff"n Billy design
I am just about done with mine. I changed a few things, most noteably the 6" boiler is now a 5" and made of steel. I have been very happy with the project. I basically only have the plumbing left to do to get it to run.
I know of a full set of castings that a gentleman might consider getting rid of if all your other leads fall through.