I got hold of a Pure earlier this year (A trader on AliExpress were selling them off at a really nice price).

I have a number of EPUB books to read on it, but one thing that annoys me is the lack of fonts I can use. I haven't been able to find any documentation about if it is possible to load my preferred font (e.g. Droid Serif). In addition the reader seems to ignore the margin settings both in the css and the device options (I want to minimise the margins).

Has anyone any info on customising the device - It's not a bad reader overall but some things like defaulting to "Large" for the font size seem just odd.

Perhaps I've just been spoiled by my original BeBook One loaded with OpenInkpot (the user replaceable battery in the One should be mandatory in all readers).

BobC
Assuming that this is the device, you have an ereader originally made by Gajah/Oaxis (with Bebook's brand slapped on top):
http://www.pocket-lint.com/review/72937-bebook-pure-ebook-reader-review

I would contact the maker directly and ask about this issue.
Thanks for the heads-up on the maker - I found this :
http://gajah.com.sg/productpage/products.php and examining the ones on that page it looks like the BK6011A.

I somehow doubt if the maker would be able to assist with this though, I was hoping that someone who had tinkered with the machine or who had inside knowledge might have some ideas.

BobC