I'll guarantee you I can build artwork that will look exactly like the original. Down to the dot pattern, dot size and off registrations. All one needs from that is vintage card stock that can easily be found and on offset printer still using the old pre press techniques. A few paper companies are also making some vintage style stocks these days due to the demand for more and more vintage looking materials. As for pre-war cards those unique printing processes are also still practiced by smaller companies and individuals albeit not a ton of them. Like I said earlier cost has always been the biggest factor but with prices getting crazy someone might be dumb enough to try it. If money can be counterfeited cards can be. Look at the lengths the government has had to go to prevent that.