I’ve emailed CU library to ask if they have McLean’s papers, to see if his translation still exists. SPCK did advertise his translation, but it never appeared. A translation was made somewhat later (in 1925) and published by Oxford University Press. This was done by G.R.Driver and Leonard Hodgson, and has been reprinted by Wipf and Stock and is available from Amazon.
I’ve always thought that the copyright status of the OUP version was questionable. It must still be in copyright in the UK and EU, since Driver and Hodgson have been dead less than 70 years. Thus the existence of a McLean translation is of interest, or so I thought until this very night.
But writing this piece has caused me to dig out my photocopy of Drivers &c. I had always thought that it was published in the UK, not in the US, which would give it 95 years protection. But looking, I see that OUP advertise their offices in London, New York and other places — which means that it was published in the US. If there was a copyright notice, this would mean that it was in the public domain now unless that right had been renewed in 1952-54. Only 15% were renewed, so the chances would be good. But in fact there is no copyright notice, which puts it in the public domain, so explaining the appearance of editions from Wipf and Stock and indeed another publisher.
So anyone who wants to scan this work and put it online may do so. Someone should. I’m tempted!
Postscript: CUL report that they have only a few of his letters, and certainly not this translation.