This is what I've found to still be in existance. If you know of any more, please email me.
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1.  Shay #4 is currenly undergoing restoration at the El Dorado County Museum in Placerville,CA.
2.  24 foot flat car #64 is part of the SPCRR roster in Fremont,CA.
3.  Railcar #10 Tally Ho is currently under restoration at the El Dorado County Museum in Placerville.
It was lettered for Camino, Cable and Northern. Now being restored to its original configuration.
4.  Combine 1002 is rumored to still exist. Loc and disp still unknown.
5.  Huckleberry RR has at least one Diamond & Caldor log flat.
6. 2022 saw the sale of a long forgotten Diamond & Caldor speeder from one private person to another. Ownership and location unknown for now. Also the possibility of a second speeder existing was raised.