Has anyone got this mod working in ZC 1.5?

I have a shop which has been around for some years, the VAT mod works fine in 1.38, but it seems to be a difficult task to get it working on ZC 1.5. The shop has the moneybookers and google checkout plugin installed, plus superorders and seo module, in addition a customized layout template, several languages and I am struggling with updates.

Or would you recommend to stay with ZC 1.38 (patched, of course)? I know of the security issues which ZC 1.38 has, as a fix I resticted access to the admin area to my fixed IP only by using Apache .htaccess rules as this shop is hosted on a dedicated server.

Any suggestions would be welcome.