The following is a study of the Coast Guard regulations concerning miniature medals. In general if there are not specific regulations concerning miniature medals, we assume that they follow the full size medals.
See the following chart taken from the regulations.
Wear five medals in a row.
Up to five miniature medals in a row may be worn. Overlap is not authorized. When 5 or fewer medals are worn, they shall be worn in a single row without overlapping. When 6 or more are worn they shall follow the description above.
There is no direct description on how miniature devices are to be worn on miniature medals, though general terms are used that imply the devices are to be distributed horizontally.
The following is an example of a five medal mount.
Wear miniature devices.
The miniature Marine Corps emblem is not currently manufactured, thus it is not currently offered as an option.
No mention of miniature medals with oak leaves.
Regulations do not say anything pertaining to oak leaves on miniature medals, we assume that miniature oak leaves are to be used.
The previous are the only device regulations that specifically reference miniature medals for the rest of the regulations please see the Coast Guard Ribbon Regulations or Coast Guard Medal Regulations.
As for the rack builder we interpret the regulations concerning miniature medals as follows: