Agree with Jürgen on the vintage.
If entirely original (which i personally don´t doubt it is, having just the pictures here to go by) this would be the very first variation of a Wilesco.
In fact so old that it could be considered a transistion engine from the WGL/HGL era, having that smooth black firebox and low smokestack support.
As far as dedicating time to search for another, i personally wouldn´t bother...
To my experience engines this rare is nearly impossible to hunt down, they only tend to come served on a platter by Lady Luck when one least expect it.