I think the installer will work on all releases. Newer versions of refractasnapshot should work on wheezy, but they might not work on jessie. There was a function to edit init to work around a change in util-linux, and that function has been removed. That should not affect wheezy.

i have several older computer running Debian Wheezy and wanted to know if it would be possible to install the (refractainstaller)
on debian wheezy to facilitate the making of an custom iso for install on other pc.

Thank you very much!