My '68 Sovereign catalog shows the numbers for a Lord Mercury as 1099 (70"), 1098 (66"), 1097 (64"). The Lord Sovereign is 1095 (70"), 1094 (66"), 1093 (64"). Visually, both bows look like your Lord Mercury except for the laminations-the Mercury has double laminations, the Soverign has single laminations.
According to my '69 Robin Hood, the Sovereign was #7178/70 (66"/70") and the Mercury was #7176/77 (66"/70"). My '67 Robin Hood shows the numbers the same as in 1968.
The Crusader isn't mentioned anywhere except in my '71 Archer's Digest, but there is no model number.