66 Corvette Conv't 427/450/M22 - Value

[Speedrx]

I am looking at a 66 Vette convertible, Rally Red/ Black, two tops, 44K miles, same owner over 30 years, orig interior, repainted in 91,, sidepipes, KO's with Goldlines, L72 450HP (early car), has M22 rock crusher ( <font color="blue">only 15 ever built </font> ), F41, power brakes, etc. Not a show car (won many local shows) but extremely nice - minor paint flaws, needs detailing. Has the original Window Sticker confirming options but engine was decked when rebuilt and has correct casting and dates codes but serial numbers now gone and the owner stamped his name on the pad. Owner said this was done many years ago before he got it when no one cared about numbers. Any idea what a rare car like this is worth with the M22 trans and confirming window sticker?