I recently bought a 30 year old Baldwin L, which is in overall excellent condition.
Greetings,
"Excellent" as in not showing wear. Ok, that's good. However, my experience with Baldwins of this vintage is that excellence is often missing in assembly. Since we are talking about voicing, even going to the extreme of acetone and plastic, I would suggest covering the basics before going all out.
A major problem is one of totally uneven string height. Agraffes either slanted or drilled with uneven holes, wire never straightened, cupped hammers traveling like sporting clays targets, and loose pinning all combine to make the mating really inconsistent. You may have an exception, but check. The weaker treble may easily be a strike point problem so check it at various points above C5.
If all you want is a little more edge, there are things you can do that will affect only the surface of the hammer, hence, easy to undo. You can try this before you do anything else. I first encountered a Baldwin that had had this treatment in a recording studio, and it was impressive. Use starch. The spray kind.
Cover everything but the hammers of one section at at time . The starch will dry out before you heat it if you try to do more than about two octaves. You move the can very quickly, from about 10 inches away, down the line slightly dampening the front shoulder and crown. (Don't point it at the end hammer when you press the button, get a running start off-target). Go lightly, It will be more like dew on short grass than a wet. wool, blanket….. Pick up a hot iron, (med. heat), and run it over each hammer once. You may hear a faint sizzle, but just barely. Within an hour, you will be able to decide if that is enough or not. This isn't permanent, in the studio the older guy said he treated it every year, along with a light filing.
It isn't a treatment for hammers that are too soft in the core or shoulder. It is a crown treatment that allows incremental changes and is less dramatic than the melted plastic. Easily reversed, cheaper, too. What's not to like???
Regards,