Removing yellow stains from pt/pd prints

Hi all, I've been asked to do some research on restoring platinum prints. I'm unsure the nature of the yellow staining, but I believe it isn't connected to improper clearing of residual ferric. i.e isn't overall staining but rather in small places. It's been suggested that a weak mixture of hydrocholric acid and hydrogen peroxide will work. Is anyone familiar with this or other methods? Any help would be greatly appreciated. Cheers

HCL and H2O2 can be used to "bleach" platinum prints. I suggest making several different mixtures of HCL with water such as 1 part HCL to 3 parts water, 1:2 and 1:1. The HCL solution is applied to the part of the print to be bleached and then the H2O2 is applied over that. Don't mix the HCL with the peroxide, mix it with distilled water. It is a good idea to have running water available or at least a tray of water. Start slow with the weakest solution and don't try to make a big change at once. When (and if) satisfied reclear in an EDTA / sodium sulfite solution then rewash the print. I don't know what your yellow stains are but I have done this on small areas of prints. Since you a restoring someone else's prints I would be very careful and perhaps practice on a print that is not important. If overdone it will be a disaster.

http://www.jeffreyglasser.com/

Here's a link to an article that the V&A published on this very topic:

http://www.vam.ac.uk/content/journals/conservation-journal/issue-08/a-conservation-treatment-to-remove-residual-iron-from-platinum-prints/