What's to celebrate, but I will make a few points for you to consider.
First of all, on an irreplaceable print, don't do anything to it until you have a scan that is the absolutely the very best you can possibly do. Take it to a lab and let them scan it at the highest resolution possible. It is your back up in case something goes wrong. It may not be exactly what you want, but at least the image isn't lost. Other methods might be to make a copy negative, or make the scan and do the digital alterations you want, then send the file to a film recorder so you can print it with ordinary black and white paper and process normally.
Second I would go make some other prints of a similar nature. Practice and experiment on those first. Learn how the particular reducer is going to work before you even think about using it on an irreplaceable print.
Third after some reading, research and many helpful comments here on another issue, using the Darkroom Cookbook for something like this may not be your best option. It is a collections of formula that might have either changed, other things found that work better, or in some cases mistakes. They were wise to warn me that just because its in the book, doesn't mean it ALWAYS works.
--- On Sat, 1/17/09, Guy Glorieux <guy.glorieux@xxxxxxxxx> wrote:
> From: Guy Glorieux <guy.glorieux@xxxxxxxxx>
> Subject: Darkroom question...
> To: "List for Photo/Imaging Educators - Professionals - Students" <photoforum@xxxxxxxxxxxxxxxxxx>
> Date: Saturday, January 17, 2009, 9:30 PM
> Hi friends,
>
> Happy New Year and happy celebration to all who will be
> participating
> physically or in spirit to the inauguration of President
> Obama!
>
> Until such time as it occurs Tuesday, I have a darkroom
> question for those
> who may still remember working with an the enlarger and
> with chemicals in
> trays under the safelight... This was probably less than a
> decade ago for
> most ...!
>
> The question has to do with the tratment of over-exposed
> prints and the use
> of reducers, such as Farmer's. Does anyone have
> experience with the
> chemistry and the results which they would care to share
> with me?
>
> I need to reduce the density (both overall and as a minimum
> the highlights)
> of several of my giant pinhole prints created several years
> ago. These
> portray urban landscape scenes that have permanently
> disappeared and I am
> trying to resurrect the paper negatives. As such, these
> are one-only prints
> and I cannot afford failure if I try to reduce them. I
> will be working with
> over-sized trays - 5 feet by 2 feet by 6 inches - using the
> roll-unroll-reroll process. I need about 4 gallons of
> working solution to
> work confortably in the trays and I will mix my own recipe
> using Steve
> Anchell's celebrated Darkroom Cookbook.
>
> Many thanks in advance,
>
> Guy Glorieux
