1960-D S/D LMC EDS DDO?

A doubled die is made a doubled die during the die /hubbing process. So a die can't progress into a doubled die. Same way with all varieties. They are on the die from coin # 1.
The marks on your coin's field are die scratches. They are not new die scratches but starting to fade. Eventually the die scratches in the fields will fade. The may some that remain next to the devices and inside the devices. New die scratches may be placed over older fading ones, but next to the devices these may still be seen.
The mark on the inside of the 6 is on most small date cents. That is one of the identifing marks I look for on a small date 1960 cent. The second thing I look for is the tails of the 9 & 6 for length. Look at several examples and you will see whnat I'm talking about.

The terms EDS, MDS, LDS, VLDS apply to die state\wear
The EDS is the first few thousand coins. The devices and field devisions are crisp. There may be some small light die scratches.

Note how strong the 3/3 is on this coin:

later die states may have the tail of the 3 missing. So the EDS examples are the highest priced and the most desired

The MDS die state is starting to show very light dies wear on the outside devices near the rim. Some light die flow may start to appear. On cent the easies way to tell is to look at the L on LIBERTY. The edge facing the rim may show slight wear in that location.

Not the devices on the area next to the rim. These areas show the most on die wear.

LDS the die flow is getting pronounced as well as the die wear on all devices especially the ones toward the rim. The edges of the devices and the fields are starting to wear away from normal die wear. The crispness of design is fading. The lesser of the preferred coins bot variety collectors.
https://www.coincommunity.com/forum..._MDS_LDS.jpg

VLDS coins have the fields/devices flowing over each other like snow drifts. These are the least desired coins. They may show very poor quality of strike even in BU. The wheat lines may be totally missing. The outside devices may even totally fade away as the fields are almost the same depth as the devices.

Hope this helps?

They are probably large dates. Compare the length of the tails of the 9 & 6's with your original coin.