Yeah I have been searching hard for a 1974 d penny because I was told that it would be worth a small fortune I have since found out that you can buy them fairly cheap but I don't know of any reverse verity's
What I know about the 1974 pennies, is that there were two hubs used that year, and that there are two mint mark types for the S mint coins. I'm not aware of any very valuable coins from 1974, other than the Aluminum cents that were made and then melted. There were a few that were saved on the sly, so that may be the type that you were thinking about. The chances of finding one of those in circulation will be near 0, but stranger things have happened. The small date and large date types for 1974 are both available in large amounts, and there is no premium for either one. There are a few sites that have good photos of the two types, and it is good to be able to tell both apart. The S mint coins have both hub types plus two mint mark styles, so pull them too, so you can get a feel for the styles of mint mark too. Look at 1972 pennies, there is also two hub types for that year, one regular and the other a master hub doubled die. The master hub doubled die is on half or more of the coins, so no added premium. On the other hand, there are over ten major doubled dies that are worth a premium for 1972 Philly cents that are worth looking for.
If you don't have it already, I would get the Cherrypickers guide vol. 1. It has a boatload of good info on Doubled Dies and Mint mark Varieties.
The column doubles can be found on 4 bays on the design. This is the normal design: The other doesn't look like doubling from what I can see. The initials should be doubled something like this:
