We elaborate on a method of G. Michler [6] to construct finite groups with a prescribed involution centralizer H using compatible pairs and amalgamation of H and another naturally arising 2-local subgroup. Modifying this approach we deal with the particular set-up leading to the simple groups GL(5, 2), M24 and He and characterize these groups as the universal completions of certain 2-local amalgams of rank 3.