In the header of most pictures you can find information about the camera that took the image, the exposition, etc.
Unfortunately those pictures have no information, probably because of the date they were taken, or, as you say, because they are "analog" pictures.
Just in case, for the next time you are in this predicament, this info is called EXIF and IPTC data. In JPG images you can also find optional comments that can be embedded in the picture.
http://en.wikipedia.org/wiki/Exchangeab ... ile_format
http://en.wikipedia.org/wiki/IPTC_Infor ... ange_Model
There are several programs to extract that info, like PIE (Picture Information Extractor) by Picmeta: http://www.picmeta.com/download.htm
A warning: you have to use a program that conserves the information of the picture when copying or moving from the web to your PC. I use IrfanView, a completely free program, that has very decent image editing abilities: http://www.irfanview.com/
LView, my favorite image editing software, also allows you to keep that info: http://www.lview.com/download.htm