It'll be interesting to know what the plans are like. I see in the sailing section they have plans for Master Hand, I have a full set of plans for this, they are in a book by Edgar March, I'm wondering could the plans be just photocopies that they have aquired from other outlets? It would be interesting to know how large the plans were, say A4 or smaller or A4 and larger. For instance the book is smaller than A4 so the plans are small meaning you would have to scale them up. Likewise I have a set of plans from Brown, Son and Ferguson in Scotland that are drawn on A1 so very large!
The drawback is that the site you mention the plans are cheap, the one I mention is quite expensive!