For all the time that I have put into my Dr.I research I have not been fortunate in acquiring any hard copies of photo yet. I think that one has to lay out some money in acquiring them. I have seen them on Ebay and some actions houses some time has albums for sale.
My collection is all digital and for me I like this better as I can see a lot more detail when I can zoom in and if needed I can play with the contrast and brightness too.
I have heard

some of the stories out there about collectors lending there collection to other people to help out in identifying the photo and them some photos would be missing and or the whole collection being copied. I think this and the whole money thing makes them hard to get.
For me I'm more into collecting the digital images and If I want a hard copy I can print out one my self. This has a better response with other collectors in the occasionally exchanging images for me. I think most collectors now are digitizing there hard copies as this is a much easier method of trading, sharing and publishing and holding on to there original (copy).
There are a lot of collections I would love to get my hand on but will never have the chance in attaining. Sorry I don't have any information on this to share but I thought it might be interesting to hear a different prospective.
Lloyd...