[Phono-L] Wood finishes

[Tom Jordan]

Let me start me saying that this is a bit off of topic (I apologize in
advance), but I need some advice from the experts. 

I am rebuilding and refinishing the case on an old machine for a friend.
Some of the wood is dry rotted and can't be salvaged.  It will be a mix of
original pieces and new replacements.

The old finish was done in a way where the striations in the oak are very
dark compared to the rest of the wood.  I have heard that this was done by
tenting the wood with ammonia to obtain those results.  That sounds a bit
out there to me, but wondered if any of you have heard of this or know of a
safer and less dangerous method of obtaining those results?
Thanks,
Tom