Foutainbleu: I know the desire to build on a custom action! I have done the calculation time and time again.

Also, the fact that you are a leftie, does not allow you to take advantage of all the pre-owned and cheap mausers out there.

I would suggest you look into the Zastava M-70 action, Jaktdepotet is selling. They sell Lefti mausers.
Now, its most definatly not a Custom action, but if you spend 10-15.000 NOK slicking it up, polishing everything that need polishing, removing writing, 3p safety, new trigger, new bottom metall.. Now, you are almost 1/2 off a new one. And the only thing missing is the C-ring feature!

Just a thought.