I'll check the dates for the others later today but the dates of the two above suggest it is the loader used by AGI. The cluster numbers definitely suggest the origin was a hard disk.
These are the ones that I think are worth highlighting at this point:
MKBI.BAT 178 29-Jun-1987 10:42:02 [cluster=6685]
BILOAD.LNK 101 29-Jun-1987 10:42:38 [cluster=6689]
BILOAD.COM 2797 30-Jun-1987 08:08:02 [cluster=6694]
BILOAD.MAP 2736 30-Jun-1987 08:08:02 [cluster=6682]
LOAD.COM 1833 29-Jun-1987 12:01:04 [cluster=6690]
LOAD.MAP 2092 29-Jun-1987 12:01:02 [cluster=6710]
MKCHECK.BAT 146 29-Jun-1987 10:40:20 [cluster=6688]
CHECK.COM 2686 29-Jun-1987 12:02:26 [cluster=6715]
CHECK.MAP 2622 29-Jun-1987 12:02:26 [cluster=6686]
LOADCHK.EXE 3457 29-Jun-1987 10:45:00 [cluster=6702]
MKCRYPT.BAT 172 29-Jun-1987 10:37:48 [cluster=6719]
DECRYPT.MAP 2620 29-Jun-1987 12:01:30 [cluster=6704]
DECRYPT.COM 2689 29-Jun-1987 12:01:30 [cluster=6724]
SIERRA.LNK 88 29-Jun-1987 10:27:00 [cluster=6718]
MKNONPRO.BAT 197 05-Nov-1987 10:52:44 [cluster=1709]
PROTECT.COM 3121 05-Nov-1987 10:54:38 [cluster=5083]
PROTECT.MAP 2807 05-Nov-1987 10:54:36 [cluster=4961]
AGILOAD.O 1546 16-Nov-1987 13:31:58 [cluster=4838]
GRAPHICS.O 441 30-Sept-1986 10:19:22 [cluster=6696]
MESSAGE.O 1070 16-Apr-1987 14:09:22 [cluster=6676]
DOSRELOC.S 5048 04-Nov-1987 10:17:02 [cluster=1655]
DOSCPC.O 1469 30-Jun-1987 08:07:28 [cluster=6728]
DOSRELOC.O 747 16-Nov-1987 13:31:30 [cluster=3484]
DOSERR.O 308 28-Apr-1987 08:38:08 [cluster=6717]
Particularly the first batch, which are all dated around the same date and appear to show several small executables and the artifacts related to building those executables. I wanted to highlight again the .LNK files, both the BILOAD.LNK and SIERRA.LNK files. It is relevant to AP86 because of the existence of AP86.LNK in a DOS directory table entry in the slack space of one of the disks.
AP86.LNK 21 07-Sept-1986 17:02:58 [cluster=342]
Hmmm, didn't expect it to be so small though. Whatever these .LNK files are, they're always quite small. I also found the details of the AP86.EXE file on one of the disks:
AP86.EXE 17742 28-Sept-1987 11:35:04 [cluster=1511]
Edit: I found another occurrence of AP86.EXE in a slack space DOS directory table entry, which gives a slightly different size and date:
AP86.EXE 18070 26-Mar-1987 16:36:38 [cluster=4876]
But its still roughly the same ballpark with regards to size.
Edit 2: I have found yet another occurrence of AP86.EXE in a slack space DOS directory table entry:
AP86.EXE 14848 01-Oct-1986 12:10:02 [cluster=52]