I too made a breakdown/dissassembleable periodesque cart. Here is a photo of me pulling it at Pennsic last year.
www.tinyurl.com/33leom
I can also be seen (at a distance) pushing it in the first five seconds of this video clip as our unit marched up to the battle field.
youtube.com/watch


It proved to be very useful for carrying everyones helms, weapons, shields, etc on and off the battlefield. Mind you, it was a bit alarming going down runestone hill with it filled with gear in the rain. Fortunately I had a couple of people to help prevent it from running away. I found it to be less alarming if I pushed the cart when going up the hill, and pulled it when going down the hill, so that I was always on the downhill side of the cart

I don't really have plans for it as such, but it is possible to see the evolution of it in my gallery at:
www.tinyurl.com/2kd9rg

I went through a couple of iterations on the construction of the wheels. They are currently made using twelve oak spokes which taper from two inches wide at the hub to one inch wide at the felloe. There is a one inch round by one inch long tennon which connects the spoke to the felloes. The felloes are made from 2x4 spruce. There are a pair of six inch wide by one inch thick discs which are bolted to each other on either side of the hub. There is no dish to the wheels. The axle is made from a barbell, and I use the barbells nuts to position the wheels on the axle.
I'm thinking of reworking the deck of the cart this year, since I had only slapped together something using a couple of scrap pieces of chipboard.
Wheels are neat and complicated pieces of technology that you really don't get to appreciate until you try to make them. Here's a neat site that documents how to make a traditional light english pattern wheel.
tinyurl.com/2dnsj2

Let me know if you have any questions/comments.

-Thorolfr

I'm going to have my fiancee take a look at that wheelbarrow and see what he says... since he'll get drafted to help with it. ;-)