As an aside - Don't forget the Inland Revenue WEN, as money earned is taxable.
I don't think that is entirely true as I would think about going down the limited route. I think you have to have a turn over of something like 64k a year**, I'll double check that however. Self employment is at 20% tax and for me, its a bit worse as well due to my circumstances, i.e. as I am on Income Support (not by choice either, was recommended by the job centre), I keep the first £80 but the rest is gradually reduced until I am owed nothing, which funny enough, is my target, owed nothing by the government.
Charities can however, use a scheme called "Gift Aid" which allows 28% extra income, but for that to happen, the Gift Aider has to be a UK income tax payer. If you don't pay income tax, you can't use gift aid.

(I know about some of it, as some of the work I do, I have to sign people up.)
I did also think about using the Class 502 to produce some sort of online sim, to hopefully get into the job market as 2011 to 2012 is more about my portfolio, unless someone knows of a games company/art company etc that is hiring.*
*Willing to relocate if needed to.
502 matters, I didn't do much yesterday as I was more interested in the A60/62 Stock, which are knackered by anyones means. Try the trackwork between Finchley Road and Wembly Park (Although I've not tried the fast trackwork from Wembly Park to Harrow-On-The-Hill.) That was fun, jumping up and down on the seat because the bogies are falling apart. Got to Neasden and the classical "Throw you out your seat" dance happens because of Neasden depot, then endured the plastic crap and was like "Oh for gods sake! These things are much worse for comfort than the A Stock with knackered seats." Got some recordings of DM 5052 though, even a whistle blast from Finchley road, I'm guessing the 502s had whistles so I might include the recording on that, plus I might try to do some even more mad things, I wanted to go to Bromley (didn't really have the desire yesterday) to take some autoannoucer recordings.... can you guess whats next? Dependent if I can script it that is. (Hence also why I wanted some Merseyfail recordings.)
Now all I need is some bogie sounds, LT bogies I can't use the recordings off because they sound soo dull (Most bogies use rubber for the primary and secondary suspension which has lead to some curious problems happening with the motor brushes, but makes the trains quieter), the CIG's have roller bearings and not horn guided, so make a different sound, so I guess I need to find a horn guided bogie on a Mk1 doing 90mph. Thats now very rare.
EDIT:
** VAT is not necessary unless the turnover is above 73K a year... I wish if I ever get to that state.