Saving Old Seagulls

Looking for a value on this Seagull. Seems to be a 58-59 - engine #CP8562. Found it at my local boat shop and considering if I should buy it. There are no dents in the tank and it seems to be in pristine condition. It comes with a British seagull stand which I have not seen before. Dealer price is "make me an offer"

Any additional info appreciated.

I guess as we are collectors we might pay more for something that is rare ie I would pay more for the stand than the motor! Motor about $200 - 350us. Does look in good nick though so may be worth more if you are keen. No clutch though. Retail so seller may expect more. I don't own any centuries Prices in US are a little higher than UK. Stand...arbitrary.