Brass polish is corrosive. It also contains abrasives, which when wicked into the mechanism will quickly damage moving parts (think sand in your engine). The only way to safely polish a harp mechanism is to disassemble it entirely, polish each individual piece, remove all polish residue, and then lubricate and reassemble.
If you wish to do this yourself, be aware that pedal harp mechanisms are complex. Every pin, disc and screw on an antique must be kept in order; they are not interchangeable. Parts are usually irreplaceable and easily broken. Please contact us for information before attempting disassembly.
The best option may be to consider the aged brass part of the harp’s antique beauty and leave it as it is, rather than damaging a rare and beautiful instrument.
If you have already applied brass polish without disassembling the mechanism, damage is already accruing. The harp must be disassembled and cleaned as soon as possible, and should not be used at all until this can be done.