A little while back, I posted Missing coins @Conder101 Narrowed it down A LOT!!!!!!!!!!!!!! Thanks!!! But he did get them all Any info on these: 1841-o $5 1975 steel clad cent 1854 c gold dollars 1793 Chain Struck in Gold 1975 d aluminum cent
I'm guessing the reader is expected to search through your posting history in order to understand not only the context, but exactly what you're talking about? Not everyone is going to understand what you mean by "missing coins".
Since someone still cannot be so bothered to address glaring deficiencies in his own threads, please allow me... https://www.cointalk.com/threads/missing-coins.308463/ You're welcome.
There were at least 15 aluminum cent struck in 1975, but they were often Philadelphia. As with the 1974's there was absolutely no authorization for any aluminum cents to be struck in Denver.