The bloke behind London coins has been around for about 30 years or so, I guess the benchmarks might be his own personal collection, I don't know, by reports though they are supposed to be quite impressive. CGS itself has graded about 13,000 coins now I think in approx 5 years is it ? No, you don't have to be certified to be a grader/slabber, you're just offering an opinion and perhaps, some form of guarantee which is a more difficult area. Then i think a 30 year collection would have been a little easier/cheaper to obtain than they are nowadays, the demand for high grade specimens have pushed prices so high that an average collector couldn't afford right now with the economic climate, hence people tend to find bargains or fill their cabinet with whatever comes along just to race to get that date run finished. A friend of mine does that, he buys worn discs 90% of the time, then tells me he's completed whatever, my thoughts were, well whats the point if its just a disc, i buy a coin to admire it, not to complete a series or date run.