Wiki has the following re ISBN:-
"The International Standard Book Number ( ISBN ) is a unique [ 1 ] [ 2 ] numeric commercial book identifier based upon the 9-digit Standard Book Numbering (SBN) code created by Gordon Foster, Emeritus Professor of Statistics at Trinity College, Dublin , [ 3 ] for the booksellers and stationers W. H. Smith and others in 1965. [ 4 ]
The 10-digit ISBN format was developed by the International Organization for Standardization (ISO) and was published in 1970 as international standard ISO 2108. [ 4 ] (However, the 9-digit SBN code was used in the United Kingdom until 1974.) An SBN may be converted to an ISBN by prepending the digit '0'. Currently, the ISO TC 46/SC 9 is responsible for the ISBN. The ISO on-line facility only refers back to 1978. [ 5 ]
Occasionally, a book may appear without a printed ISBN if it is printed privately or the author does not follow the usual ISBN procedure; however, this can be rectified later. [ 7 ]
So I'm guessing the answer would be no. ISBN would be the same here. Will get round to adding Mr Tim to the AC bookstore.
RE: "There's a website (which I'd never heard of) called www.deastore.com " Ditto and likwise