Nice tones Andy. Pickup and John's preamp tube advice will definitely make a difference. Don't under-estimate tuning to E-flat too, a lot of the VH tones comes from the spanking of 9 gauge strings on frets and maple and will also hit the front of the amp with a different EQ making it a little tighter and crunchier too. If your looking for that VH thing of course.
The best VH sounding amp I ever had was a 100 Watt Marshall Rockstah Mod 5, that amp nailed it. Here's a clip I did a long time ago when I had the amp and it was at a reasonable bedroom volume. I'm no Eddie but it was fun tone chasing him.
http://www.youtube.com/watch?v=mY72CRDQe7k