There are multiple older translations, but Project Gutenberg only has one at the moment. I'm conjecturing that they used to have a different one (also out of copyright; that's their whole thing), but have taken it down for unclear reasons.
It's also possible that I found a free translation of The Three Musketeers somewhere else, or that I read the same version PG has now and have misidentified it as being different.
It's also possible that I found a free translation of The Three Musketeers somewhere else, or that I read the same version PG has now and have misidentified it as being different.