Morris Minor Owners Club

I've nearly finised all the steel work on the trav one or two little bits remaining but my mind has started to wander towards the wood. Its generally not too bad but,

on the drivers side the bottom of the B post, is completely rotten and the rail on the bottom is knackered too (the wheel arch section seems ok thak god)

I'm not really too keen on pulling all the wood off the replace the B post but I definately need to let a new section into the bottom of the B post and replace the bottom rail. Any ideas? I don't have a clue where to start!

if u were closer i could splice a new peice of ash in for you

Thats what I was thinking but I wouldn't have a clue how to do it. I'm not a complete dunce when it comes to chippy work but this is beyond me.