You can find the Forge world Drop Pod moddels here..
Forge World SPACE MARINE SUPPORT
Sorry but citadel (GW) dose not make plastic drop pods moddels.. there was a white dwarf that explained their construction in 1998 and again in 2000.
There is a company not asociated with GW games that is in Austrailia that makes a wooden Drop pod but if you bring one of them to the table at an official game, GW can Ban you from ever entering a Gamesday, Golden Demon, or Grand turnament.
Austrailia has difrent Copy protection laws than UK even though its part of the commenwelth. They have not been able to sue that buisness out of existance. l
Aso in Austrelia you will find a realy old partner of GW called Armorcast and there are some Legacy circa 1989 drop pod moddels from Armorcast But they are higly colecter "never out of box" expencive and monstrously ugly as all armorcast moddels for GW were / are.
The original Armorcast company got sued out of existance as it was also partners with FASA for the Batteltech Mechwarrior game.. FASA had stollen IP rights to art of Robotech saga for the battle Moddels of its games. After 10 years latter it had to fork over 75 million dolars to Bandai Manga Inc .. Armorcast had been contracted to build the resin casts for the moddels of the FASA game never knowin their origins.. They lost about 8 million and the name of the incorprated company was all that was left. Someone a or more year ago bought the right to the name and started using it to make new moddels for other games..
I hope that answers your questions.