A Bank of England 193? Ten Shilling note (Series A - red/brown)(Chief Cashier B. G. Catterns - serial V99 281094), uncirculated and in absolute mint condition could fetch anything up to £320 GBP. If it has been circulated but still in good condition, it might fetch anything from £80 to £200 GBP.
A reputable coin dealer will be able to give a more accurate valuation.