Note that there is VIN of Solaris (SUU241160EB013339) and not of Skoda! These begin with TM9.I guess this means that the Skodas in Burgas are actually using the Solaris' VIN numbers?
All buses sent to koda Electric for fitting propulsion equipment, irrespective of they are Solaris, SOR, or Iveco, are complete buses with no propulsion only and have their own VIN's. As koda wishes to continue its traditional brand name, these sold by them (presently 24Tr to 31Tr) obtain the second VIN of koda.
In other cases, when E only fits the equipment to trolleybuses sold by bus makers, they remain by their original names (as Solaris Trollino) and VIN's (as Cagliari, Coimbra, Landskrona, Lublin). Your trolleybuses were bought from E and presumably Czech VIN's are used (invoices, etc.).
By the way, when 61th koda was taken into service in Sofia (2680), this city became the biggest user of Trollino
trolleybuses, leaving Lublin at the second place with 60.