I reckon one of the real strengths of this forum is it's unchanging continuity and very light touch moderation. Apart from one or two technical bells and whistles, I'd say it was virtually the same as when you last posted in 2008. I joined in 2009.
With regard to the coin's value, I can't really help as I'm not a farthing specialist. All I can say is that Peck lists BMC 525 as "extremely rare". Given the auctions you mention above and the recent rise in coin prices, probably £300 is close to the mark.
I'd say provenance or pedigrees are still very important. Collectors really value provenance, especially those that go back a very long way. The one you have, albeit scribbled out long hand, is very detailed and comprehensive.
ETA: by the way I'd just add that with regard to the Coins and Banknotes specimen, Eddie Price does tend to charge top dollar for his stock. He does have some very very high end stuff though, and I notice that the ex Bamford F21 penny he was offering for £2,750, has now disappeared from his website. It doesn't say sold out, it's gone altogether.