MWF is looking like a good candidate here.
Honestly it's more about getting a similar experience than anything else. Even if it's not the same formula, but is created in a similar way. Or perhaps even created in such a way as to imitate older soaps E.g: less of "modern industrial processes" and "modern scents"...iirc 18th and 19th cent. scents used to be much more subtle than they are now. It's interesting to note though, that basically no soap recipe has survived more than 100-150 years?