I have just been given a Zeiss Ikon Ideal 250/7 in near mint cindition, I have just spent the last 6 hours stripping and cleaning it. After all that the film back/holder/slide (don't know its correct name) although Zeiss and no number on it is not the correct one as it is too small. I have searched the internet but am now more confused than ever. Can anybody help me find what I need. I currently use a Bronica ETRS, Rollie 35s and sorry a Nikon D300. I love film and more importantly B&W.