I've only read a little of this story online a while back.
Basically the crew of a spaceship encounters an odd spaceship, which upon closer inspection is made up of much smaller ships. (Kind of like the swarm ships from Star Trek Beyond).
I'm definitely sure this was published in the '30s or '40s, because it was one of those sites which had PDFs of old pulp magazine stories.
Can anyone please help me find this story?