That could well be a cockup, it is possible that the diesel turbo can be used on a petrol and give lots of power and use the original carby (you'd have to configure it as a 'downstream' or blow through the carb, as the diesel turbo oil seals are not designed to be subjected to vacuum, the other thing is the 'AR' ratio of a diesel turbo is probably totally incorrect for the petrol), but to do that at the very minimum you would need low compression pistons, if you just bolted on a charger you'd get pre ignition at anything above very low boost pressure blowing holes in the pistons and melting valves.
I suspect this guy has bought this thing off someone who's just bolted it on, the petrol manifold can be fitted to the 200 tdi, people have done it with the 200tdi conversion, so I'd think from that the tdi manifold would fit the petrol, thats what this probably is with turbo.
Without knowing the engine has been prepped for a turbo, which we dont I'd advise anyone to keep clear.
Andyb from whatsits motorsport would probably know how it should be done.