OK, so I feel a bit foolish. When I checked my progress yesterday, I was here at work, so I didn't have access to my Playstation (I.E. the actual logbook). Thus I didn't realize that I actually hadn't collected my rewards yet. So, when I got home, the gear was there waiting for me to collect it, and I, at least, am a happy camper (was able to finish the rest of the logbook yesterday, so now have the sweet sparrow, as well as the gear). It does seem, however, that my question brought out others who faced the same issue I thought I was having. And the solution does seem simple, why not just let us purchase the gear from Tess (or Holliday) for legendary marks once we've earned it?

i have the same problem i had no inventory space either when i completed the requirment and i had no idea that i didnt have space nor that i wouldnt get it back, bungie plssss i need this helmet to complete my set

I'm in the same boat. I got the momentum guard warlock helmet and was going for the whole set. Later I got a random srl helmet and went to dismantle it, only to realize my inventory was full and the last one I was holding was the momentum helmet. I'm really mad at myself and kind of salty that I can't buy it from holiday like the quest gear.