A Bank of England Ten Shilling note (Series C - red/brown)(Chief Cashier J.Q. Hollom - serial Z15), uncirculated and in absolute mint condition could fetch anything up to £16 GBP. If it has been circulated but still in good condition, it might fetch anything up to £8 GBP.
A reputable coin dealer will be able to give a more accurate valuation.
If your Ten Shilling note has Queen Elizabeth II on the obverse and a large image of a seated left facing Britannia on the reverse, a serial number commencing with S74 would be Chief Cashier J.Q. Hollom, possibly printed in 1963.
A Bank of England 1963 Ten Shilling note (Series C - red/brown)(Chief Cashier J.Q. Hollom - serial Y06), uncirculated and in absolute mint condition could fetch anything up to £7 GBP. If it has been circulated but still in good condition, it might fetch anything up to £4 GBP. A reputable coin dealer will be able to give a more accurate valuation.
A Bank of England Ten Shilling note (Series C - red/brown)(Chief Cashier J.Q. Hollom - serial M48), uncirculated and in absolute mint condition could fetch anything up to £50 GBP. If it has been circulated but still in good condition, it might fetch anything from £11 to £25 GBP. For the Ten Shilling note issues of Chief Cashier J.Q. Hollom, the serial range M19 to M55 were replacement notes, a reprint of a note if it was spoiled during the printing process. These notes would be of special interest to collectors. A reputable coin dealer will be able to give a more accurate valuation.
J.Q. Hollom was the Chief Cashier for the bulk of the period 1962 to 1966. L.K. O'Brien for the early part of 1962 and J.S. Fforde for the later part of 1966. Any reasonable attempt at a valuation would depend on the condition of the note and the serial number.
A Bank of England Ten Shilling note (Series C - red/brown)(Chief Cashier J.Q. Hollom - serial 26H), uncirculated and in absolute mint condition could fetch anything £8 GBP. If it has been circulated but still in good condition, it might fetch anything up to £4 GBP. A reputable coin dealer will be able to give a more accurate valuation.
A Bank of England 1963(?) Ten Shilling note (Series C - red/brown)(Chief Cashier J.Q. Hollom - serial 17B), uncirculated and in absolute mint condition could fetch anything up to £8 GBP. If it has been circulated but still in good condition, it might fetch anything up to £4 GBP. A reputable coin dealer will be able to give a more accurate valuation.
A Bank of England Ten Shilling note (Series C - red/brown)(Chief Cashier J.Q. Hollom - serial T25), uncirculated and in absolute mint condition could fetch anything up to £7 GBP. If it has been circulated but still in good condition, it might fetch anything up to £4 GBP. A reputable coin dealer will be able to give a more accurate valuation.
A Bank of England 1963 Ten Shilling note (Series C - red/brown)(Chief Cashier J.Q. Hollom - serial 01C), uncirculated and in absolute mint condition could fetch anything up to £8 GBP. If it has been circulated but still in good condition, it might fetch anything up to £4 GBP. A reputable coin dealer will be able to give a more accurate valuation.
A British 1966 Ten Shilling note (Series C - red/brown)(Chief Cashier J.Q. Hollom - depending on the serial number), uncirculated and in absolute mint condition could fetch anything up to £32 GBP. If it has been circulated but still in good condition, it might fetch anything from £2 to £18 GBP. A reputable coin dealer will be able to give a more accurate valuation.
Philip Hollom was born in 1912.
A Bank of England 1963 Ten Shilling "replacement" note (Series C - red/brown)(Chief Cashier J.Q. Hollom - serial M35), uncirculated and in absolute mint condition could fetch anything up to £50 GBP. If it has been circulated but still in good condition, it might fetch anything from £11 to £25 GBP. A reputable coin dealer will be able to give a more accurate valuation.
A British 1961 Ten Shilling note (Series C - red/brown)(L. K. O'Brien - serial A37 315961), uncirculated and in absolute mint condition could fetch anything up to £12 GBP. If it has been circulated but still in good condition, it might fetch anything from £3 to £9 GBP. A reputable coin dealer will be able to give a more accurate valuation.