Nice looking machine.
WRT your slipping seatpost, it didn't matter how much I tightened mine when it was new, it kept slipping down.
I resorted to a light sandpapering of the bottom of the seat tube to give it a rough surface and therefore, something to grip.
I know it's hard to start attacking your pride and joy immediately after you've bought it, but this worked for me.
Hmm.. thank you -.sounds like something that will work but what is the seatpost made from? Is it alu?