They used to sell RWS Berdan Primers in the US. I have several sizes that total about 1500. You need to know what size and what cartridge they will be used in, then check with The Western Scrounger to see if they have them. (Older RWS cartridge info says what primer they used)
Primers are considered an explosive by many countries, so by themselves they are harder to get through most customs inspections without "Paperwork & Permits" (AKA Bribes)
I have a 450 3 1/4" NE double rifle. In the mid 80s I picked up 100 Kynoch empty brass and 4 sealed tins of primers (250 per tin). [This was at an OGCA meeting, not many gun shows like that!] All were brand new in 1962! They were and are stored properly and still look new. This is the "Hottest/largest primer Kynoch made, and was used in everything large! including 600 NE. After production stopped, the ammo manufactures switched primers to the Federal 215. (now the hottest primer in small arms) My RWS primers on the other hand were in cardboard sleeves and sat open at a gun shop and before that is unknown and quite suspect!
Ivan
I have the RCBS Berdan Decapping tool, you are better off with a tight fitting steel rod and use a center punch on the edge. Hornady makes (special order) a decapper for each cartridge that you fill with water hand hit with a hammer to push the primer out. This system is what Lapua uses to reload Match 6.5 by 55 ammo at the factory.