Some clues, each require a little digging into the bike but nothing difficult.
Most obvious are the needles. Remove the top of #3 carb and take out the throttle slide. Remove the needle. If it has SD-129/SD-130 stamped around the top, it's standard. A Dynojet needle has 8 e-clip grooves but you don't find many DJ kits fitted to Fazers. If it's non-standard, 99% sure it will be Ivan's.
A modified airbox lid and performance air filter would indicate Full Monty Ivan's install but you'd need to check the needles to be sure.