Well, OD is a 12-man raid, and raids will be quite tricky to solo, if possible at all. Wound wing will definitely be impossible without at least 3 people due to mechanics, disease wing mechanics require at least two people as well (not saying those can be done with 2/3 people). Mind the minimum level for it is 65, and even 6-mans at that level can be very challenging to solo.
Barad Gularan on the other hand is quite soloable as it's "only" a level 50 6-man instance (maybe depending on class, needed a few tries with my champ at 75 due to boss pushing the I-win button, but finished it first try with my guard on 85), just like Urugarth or Carn Dum.
Used to play: 85 Champ / Captain / Runekeeper / Guardian, Guild Master of everything but cooking.
Playing now: Hellcat / King Tiger / GW Panther / IS / KV-5 / M4 Sherman and more