Those arms were cast by a guy in Siberia, in resin. I'd name him, but unfortunately he went on to produce non-licenced copies of BT stuff, which is alas verboten.
Might be worth checking W40K parts - there are some Imperial Knight weapon pods that might work well. If you have access to MW:DA stuff, you could probably bash something out of the big LRM-20 pods you get on JES IIs - two of them would be 40 missile tubes, close to the 45. I did this for my Night Gyr D:
Except I misremembered the pods from the Nova Cat B, the Night Gyr's ones are supposed to be chest-mounted, so I just call this a custom config ;)
