You should also deduct incidental cots of disposal in amount of 500£. Gross sales proceeds 12.000£ -Incidental sale costs (500)£ -Costs (6.000)£ =Chargreable gain 5.500£
You cannot claim a 1.000 £ small pool WDA because it refers to a special/main pool balance. Since your balance is 5.800, you cannot claim small WDA. If it was lower, you could.