SERIALNUMBER AND A PICTURE WOULD IDENTIFY THE YEAR
THE TAMERLANE WAS MADE FROM 1963 TO 1968. THE HC 30 WAS 1966 (?) AND THE HC 300 WAS 1967 THROUGH THE MID '70'S THE VALUE WILL BE DEPENDING ON THE YEAR, THE RISER MATERIAL AND, OF COURSE, THE CONDITION. AS A GENERAL RULE, LEFTIES DO NOT BRING AS MUCH AS RIGHTIES.
LIKE FINE ANTIQUES THEY ARE WORTH WHAT SOMEONE IS WILLING TO PAY. NO MORE, NO LESS.
YOUR BEST BET IS TO FIND ONE LIKE IT ON EBAY THAT HAS ALREADY SOLD. SEE WHAT IT WENT FOR. HOWEVER, THERE IS NO GUARANTEE THAT TWO IDENTICAL BOWS WILL BRING THE SAME PRICE.