Welcome aboard Jim, and I hope you have many happy miles in your XKR Convertible - Zero. As you will note if you have already been trawling in this section of the Forum, there is a lot of knowledge and a willingness to share this with fellow Enthusiasts.
If you have already suffered from the dreaded tin worm on your unfortunate XJ, then I am assuming that you had the underside of Zero fully checked out ahead of purchase. The main body may be aluminium, but that doesn't guarantee no corrosion, just a different version, but the underside has steel subframes that can get into a really poor state very quickly. This is especially the case if the car has been used year round and seen salted roads or, strangely enough, if the car has spent some of its life living by the seaside.
Let's see a few photos when you can.
N6 JMX