Many thanks for your advice. The reason for my interest in this item was that the body is in fairly bad shape and is 'almost' thrown in; my prime interest was the lens. I have a 150mm, 80mm, and 65mm for the M7, but find that the 65mm is not quite wide enough. I thought that if the lenses were interchangeable it would provide me with the wide angle for the M7 (and a nice spare backup body). Since they are not, I won't buy.
Micheal: I know your comment was not meant is all seriousness, and it would be nice to have another quality camera lens setup, but as Sandy points out, it would be seriously expensive (M6/7 lenses the price they are). I have also come to the conclusion after 20 years that it is better to use 1 or 2 systems well, than to use a dozen badly. I have an M7 and a 4x5 and that is all I want since both are great boxes with even better lenses and cater to all my needs. (OK, I have a Pentax 67/80mm macro for 120 closeup, but I haven't even seen it in years.)
Don: I have also heard the same. Thanks for the comment.
Thanks again everyone. Much appreciated.
Geoff.