Pleurothallid-esque
 

When a person who had a long-ago commercial greenhouse passed away in her late-90's, her daughter sold off her orchids (at bargain prices). Most of her stock is species, so I am supposing this is one.
Anyone have any guesses I might pursue? The buds emerge from a fairly woody sheath, I cannot detect any scent. Resembles Restrepiella (the snake head) except for the color.
4" leaves atop thin 3" pseudobulbs; flowers about 1/2", open green, fade to yellow. The latest flower has lasted about a week so far.
TIA - Nancy

Restrepiella ophiocephala?

They're highly variable.

You can also try and see if you can get a positive ID from a botanical garden who's willing to do it.