chair restoration/paint removal  

I
know of no paint removal technique which preserves the layer beneath. The only possible success would come with paint layers of different formulation, where (for instance) the removal of shellac, which dissolves with alcohol, might not affect a coat of lacquer underneath. (No guarantees -- don't try this at home !)
The use of all paint removers that I am familiar with, dissolve all paints down to the bare wood or metal.

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It may be possible to "scape" the top layer of paint of and then try to restore the original layer of paint with a product like T cut. If I were you I would strip the chair bare and then spend some time finding an exact match for the original. If you post a pic it would help. The chances are it was apinted because the original finish was in bad condition?

There is a chance --...
There is a chance -- depending on the makeup/quality of the top coat -- that you could possibly remove the layer with heat. Very unlikely, but possible.