hap,while this CAN be done,as is described on pages 154-155 of Jerry Kuhnhausens Shop Manual,it seems finding a replacement cam,would be difficult. I have checked several parts catalogues,and none are listed separately from the entire hammer assembly(less roller).
Some hammers have the cam forged as part of it,and if this is your case,it would involve grinding it smooth with hammer side,then drilling the EXACT size hole,in the EXACT location(tough to do without a jig,or pattern hammer to go by).
If the cam is replacable,then you punch or press it out,clean the hole,and apply a Loctite adhesive to the cam & hole insert,and let sit for 24 hrs. Then you "fit" it to proper height/diameter.
While SAA hammers,even used,are NOT cheap(you didn't say what generation yours is?) it might be a cheaper way to go,assumming you could even find the cam,and most importantly a gunsmith who COULD do the job proper,as it seems time consuming,which equals $$$!
Just a caveat on used SAA hammers however,that you buy "online",without persoanl inspection;some are "beat" and may not fit your SAA without more modifications to the other parts to ensure correct and smooth timing.
Good Luck,and hopefully there is a qualified gunsmith in your area.
Despite what some "Cowboy Shooters" think,SAAs require fitting of their parts,not the "drop in",or parts changing,as when some of these guys were shooting semi autos-even on these a little fitting is usually required for flawless function and smoothness!
Bud /forums/images/graemlins/confused.gif /forums/images/graemlins/wink.gif