Slight correction on the previous post.
The basic Ivan's installation uses what he terms as the Slip-On kit. This one was the original kit that Ivan created which works with either the standard exhaust can or an aftermarket can. Once installed, you can switch between cans without having to make any adjustments to the carb settings.
A year or two after the Gen 1 hit the market, several different aftermarket performance header systems from the likes of Akrapovic, Yoshimura and Muzzy became available and Ivan came up with a second jet kit, the MB kit (stands for Modified 'Box - ie, airbox) which has larger main jets than the Slip-On kit and also a different needle profile.
Ivan subsequently found that his MB kit could be fitted to a Gen 1 with stock headers and a less restrictive can and that provided certain other mods were made to the airbox lid, the air filter and the intake stubs, this gave gains almost comparable with the full aftermarket header systems. This is the installation which became known as The Full Monty in the UK.
To check which version you have installed, start by checking the airbox lid and air filter. If the snorkel inside the lid has been cut in half and you find a K&N or Pipercross type filter, you almost certainly have a Full Monty set up.
If the airbox lid and filter are standard, you could still have Ivan's Slip-On kit installed. To confirm this, remove one of the carb tops and take out the throttle slide. Look closely at the spring. If one end has been clipped it will be obvious. The standard spring end coils form a perfect circle; a clipped end will be bent down by about 30 degs and will not look the same.
If you're still unsure, look at the needle profile. If it is tapered but totally constant along the exposed length, it's probably a stock needle. Ivan's needle is made of polished steel and has subtle but noticeable variations in diameter.
Hope this helps.