Which brake posts do I need? I have a Schwinn Rocket mountain bike with front and rear V-brakes. While removing the rear brakes to be replaced with higher quality ones, I managed to twist one of the brake posts out of the frame while it was still attached to the brake itself. It appears that the brake/post bolt is seized and won't budge.

How much effort should I invest into separating the bolt, brake and brate post trio? The whole train wreck is soaking in PB Blaster overnight, so I'll try one more time tomorrow.

It seems to me that a brake post is the type of hardware that I should be able to buy at any bike shop. However, as with anything coming from the highly balkanized bicycle industry, I'm wondering whether there are many sizes of brake posts out there. How can I tell which one I need?
I recently looked (in France) for break post studs and it was surprisingly difficult to find them. The only place I found it was a bike shop that would sell and repair the same bike I had to repair.

The major things that distinguishes break post studs are the diameter and the thread. There are many models (Is it proper to link to shopping sites that sell those kind of parts to show the kind of models?).