You're welcome. The second link I listed gives indication of values depending on grade. Checking what they sell for on ebay is also a good way. Maybe some Numista members with more knowledge of banknotes will reply also.
The Waterlow & Sons red series from the 1960’s (that look older with the Roman Numeral markers) are very popular & in short supply. Demand always exceeds most dealer’s stock so these Series B “c” versions go for at least $30 (or more) in VF condition like your note. DON’T press out the vertical folds - your note looks original & flattening it out will not make it more sought after (but quite the opposite). Very attractive example!