I have regularly found that the items listed in the dealer's parts books do not match the parts on my truck.
If sourcing parts online, I try to find listings that have actual images of the part being sold, opposed to simply relying on the part number alone.
Not always possible, but this approach generally results in getting the part I want.
As an example, regarding this specific part, I see that Mitsubishi seem to use the same part on different vehicles.
Look at Pajero/Shogun (2000-2006) with the part number MI4068. If this is identical to the part on your truck, it may be a cheaper option than a Fuso listed part.