I had a B26 tip and broke some of the pins.... When I went to get a replacement, I learned that they were discontinued.
After kicking a couple of ideas around, I came up with using the Dell charger adapter that is used to charge the unit without the docking station (Dell part number T6207) and getting iGo tip A54 for PSP/Zen Vision M's.
Luckily I still had my T6207 stuck in a drawer somewhere, but I found two sites that list them for sale.
Alan CompuTech International
Charger Adapter for Dell Axim X50/X50v Handhelds - Power Solution
The iGo tip can be found anywhere the tips are sold, such as Radio Shack.
All the specs seem to line up close enough. So far it seems to charge ok, but I haven't been using it long. Hope this helps.
Randy