You need to replace those files in the /webassist/ folder, not in the /installs/webassist folder. I think that is why you are still having the issue with the https:// redirect.Copy all of the files from /install/webassist to /webassist and upload them and it should work properly.

I did the list above show the local location of the file, I have just deleted the contents of /webassist/plugins/shopping_cart on the remote server and uploaded the files from the 057 beta zip and I still have the https issue
I didn't add tax and shipping to the express checkout process... since you can change your shipping address on that page they may not be accurate, so adding them could be just as misleading as not. 
Fair enough


