Unfortunately Visual Studio Gallery does not support "previous" version download (bug report is hanging around from 2011). You may need to request latest 7.x version of plugin from EPiServer Support.
Thank you for your reply.
In the end I created my own nuget package for Alloy 7.5
Not ideal, but saves time :)
I have Visual Studio Extension for EPiServer CMS 8, but I'd like to create an Alloy MVC solution for EPiServer 7.5
Is EPiServer Deployment Center my only option?