I have no issues with anyone making a profit or buying cheap and selling for the actual worth of an item. This probably isn't a good time of year to try to sell this frame, or any other frame. But, I think you might be asking a bit much. To illustrate; I recently bought a Mercian in similar condition and degree of collectability for half the price you're asking, complete with BB and headset. The price you are asking is 'collector only', there are many usable frames out there for much less. It is a lovely frame, but you'll either have to be patient or drop the price (the £425 you were offered was a good price), maybe re-advertise in April. Sorry to be negative, I'm trying to be realistic.
I have no issues with anyone making a profit or buying cheap and selling for the actual worth of an item. This probably isn't a good time of year to try to sell this frame, or any other frame. But, I think you might be asking a bit much. To illustrate; I recently bought a Mercian in similar condition and degree of collectability for half the price you're asking, complete with BB and headset. The price you are asking is 'collector only', there are many usable frames out there for much less. It is a lovely frame, but you'll either have to be patient or drop the price (the £425 you were offered was a good price), maybe re-advertise in April. Sorry to be negative, I'm trying to be realistic.