Is the chrome rod pointed roughly up or down?
If the chrome rod is pointed up (emulsion type), rebound only, its at the top (IMO far and away the most important knob...). Think some of the M1100's shipped with Ohlins of these sorts...
If down, bottom - rebound's at the end of the chrome rod either way.
Does yours have an external reservoir? Generally, if there's an external reservoir there is compression adjustor(s), they're at the top of the reservoir. If not, no compression adjustor. This is a production issue - on compression, oil displaced by the volume of the chrome rod entering the shock body is metered through a compression adjustor valve into somewhere - with reservoir, easy to design and manufacture a place for that oil to go (and to place a valve to meter it), without reservoir much more difficult (though if I recall correct, Penske has a non-reservoir variant with both rebound and compression adjusters at the end of the rod).
Hope this helps