И всё-таки, почему они больше не называются Икарусами, пусть даже Ikarus-EAG?

А какая существует? :)

Если честно - мне самому непонятно, какая фирма их производит.

The Ikarus EAG factory was closed down in December 2007. ;-)

They are technically registered as Webasto Hungaria S91, but the factory itself is called Molitusbus. They are even called Raba S91, because their underframe is from Raba. Since there is no exact name, I simply call them S91.
So far there have been built 2 prototypes and 5 buses delivered to Norway. The last one is a demonstrator for Norway and Sweden.

пусть тогда будут Webasto Hungaria S91, как оформлены по документам