Mistakenly deleted Google Play Services?

I've got the original (AFAIK) Android 2.3.7, rooted, running on my 5860E.

Recently, when I try to install anything from the Play Store, hitting the Install button doesn't do anything except produce the following error message in my notifications pull-down menu:

Error retrieving information from server:

(Not sure if the last line is always the same, but it's at least close.)

I think I carelessly deleted Google Play Services using Clean Master just before this started happening, so that's probably what happened?

1) How can I, presuming I decide it's necessary, re-install Google Play Services? (I'm quite familiar with ADB!) Also, can I install it on the SD card instead of on the phone itself?

2) Are there alternatives to using Google Play Services?

I realize that these questions might be dealt with in a less device-specific forum. Any suggestions?