maintain older unison 2.40.x via homebrew -

I have a fully functional input version (2.48.3) that I had installed with a homebrew. So far, so good. But I would like to synchronize a folder with a remote machine on which the confluence of version 2.40.x has been installed. I do not have root access on this remote machine, so I was thinking the weather was a convenient way to install 2.40.x on my local machine and I know the weather better, it can be kept by the homebrows.