Very good advice, Scott -
Unfortunately, I lack a bone fide image editor, like WinImage. However, I came across a free application called Virtual Floppy Disk (VFD) at:
Here's how I handled a set of 2 floppies using VFD:
I used MKBT to load the boot sector of the first bootable floppy into a virtual floppy drive, which as created using VFD as a 2.88MB drive with the drive letter B:
I then copied the files from the first bootable floppy and the second floppy (except for autoexec.bat and command.com) into B: and used Notepad to make your recommended modifications to the autoexec.bat from the first floppy disk.
The resulting contents of the B: drive are files from both floppy disks. I then used a utility included with VFD to save the contents of B: as an image file, which is bootable and can be included in the Ultimate Boot CD.
Thanks again for your help!