Weylan in the first movie was a typo? Was it supposed to be Weyland in original designs and whoever was doing graphics was in a rush? Like when they wrote "insure return of organism" instead of "ensure" hahaha. Or was it whoever was doing the second movie who was in a rush and didn't double check? Does seem like a weird mistake!
Ron Cobb cribbed Weylan from Leyland and made the Company logos for Aliens (from an unused design made for Alien IIRC), so I think he re-inserted the 'd'. The name doesn't appear in the scripts, for one.