I've a `~/opt/gambit` (4.9.5) bonsai now and the results look consistent with 4.9.5 at home and the C version now:
------------------------------------------------------------------------ (yeti@tilde.institute:p3)~/gambit$ sha1sum mb2*out | sort 2afc568d51b567a515f8d8197d7606351fce9ebc mb2.scm.v4.9.5.out 2afc568d51b567a515f8d8197d7606351fce9ebc mb2_tcc.out 2afc568d51b567a515f8d8197d7606351fce9ebc mb2ce.scm.v4.9.5.out 48ddbd025206b0cab9cfedaa48d075daa56ce685 mb2.scm.out 48ddbd025206b0cab9cfedaa48d075daa56ce685 mb2ce.scm.out ------------------------------------------------------------------------
`mb2.scm.out` and `mb2ce.scm.out` are the broken 4.9.3 outputs.
4.9.3 from OpenBSD's ports may have more "surprises", I still suggest to deinstall it.