There is much, much more vintage rally activity in Europe. Every weekend and everywhere. Your strategy is probably good. Autoscout is like the Walmart of all of Europe and Mobile.de is like the Walmart of Germany but you can find everything and if someone is serious, a "detailed search" will produce your car. Classic Driver tends to profile upper end dealer inventories and auction lots. I think Mobile.de is your best bet based on my own experience buying from it. Hate to say it, there is also Ebay. Everybody from Europe looks there but the risk is an unsuccessful sale. You can have a car sit on Mobile.de for a long time and not a problem, just hasn't sold yet. Unsold history on ebay is a scarlet letter for some reason. Good luck!