You can't under or over clock a Compaq. If it crashes on 98, it's going to crash on 95. 98 has the same 2.1 GHz issue but there's a workaround, M$ is going to charge you for the patch.
http://support.microsoft.com/default...b;en-us;312108
If you need a true DOS box, go dig a 486 or a classic Pentium out of a dumpster.