How do we add old books to GR that don't have ISBN?

[Orinoco Womble (tidy bag and all)]

I see a lot of books from Gutenberg etc here, that were published before the ISBN system. I'd like to add a few that were published in the 1920s etc but have no magic numbers. How do we do that?

[Pete]

No idea - but I've got another question. My latest ebook, when uploading it to Amazon, didn't give me the tick box to get an ASIN number. I notice it's got one on the publicity page, but I like to get one, insert it into the book on the 'copyright' page and then submit the text. So now anyone can copy my book and there's nothing to say it came from Amazon.
(I suppose now I know the ASIN I could resubmit the text, but that's not the point. Why is the tick box missing?)