Since you live in Norway, I've got believe it would be one heck of a lot cheaper for you to find a machine shop in your local area, if not country, rather than having a still very heavy flywheel shipped from the USA to Norway. Even per cargo rates on a ship this would be very expensive. It's not just the weight of the now-lightened flywheel that you need to consider: it and the clutch will have to be put in a wooden crate (which you will also pay for) and then sent to you. And don't forget the import duties that will most certainly be tacked onto your costs. Check the shipping rates for about 80-100 pounds, depending upon how heavy the crate is.
As far as you getting the work done in your neck of the world, check for racing machine shops or specialty hot rod businesses. Surely there must be a couple in Norway!? I'm sure one of the machinist guys on this website who has done this modification could provide the details on how much to take off, where it should be removed and provide the new bolt pattern for the V-8 clutch. I have a un-mounted lightened flywheel here from ACR in Skokie, Illinois, that I could take a bolt pattern from for you to use on your lightened flywheel. I' can take pictures of it for you so that your local machinist can use them as a guide. The V-8 clutch could most certainly be ordered from Germany or Denmark, where Model A's are not uncommon.
Also, check with Leif Rust (sp?) in Norway. He's a big Model A guy and can probably advise you where to get the flywheel work performed. I believe you'd be money and time ahead getting this work done in Norway.
Marshall