Excellent idea Russ. I do not own a Rekord pistol but have had quite a few in for repair over the years ,and obtaining spares has always been a problem.
The thing to remember is that these pistols are much rarer than say Webleys ,so it may take you years to recoup your outlay.
Although, you would undoubtedly sell some spares on that internet auction site.
In my experience the main parts failures are cocking links and seals, so those are the parts I would go for the most.
Pete.