Forum:Claptrap upgrades - any way to get them after completing mission?

OK, I've stuffed up! I've been playing through playthrough 2 (on PC, playing solo) and I've done 6 of the Claptrap Rescue missions, and I've only received one Backpack SDU (I've only got 45 slots in the Backpack). I see from reading the Wiki that if I'd Ctl-Alt-Del the game I could have kept retrying it until I got the SDU, but I didn't know this at the time. Is there any way for me to get the upgrades now, or is it too late? Do the Claptrap Rescue missions become replayable in Playthrough 2.5?

Having only 45 slots sucks - in the big missions I keep having to drop low value items to make room for better gear.

Cheers!