I found a GOOD work-around for what I want.
I dd'ed the hybrid iso TinyCore-7.2.iso to my /dev/sdx with
dd if=$(path_to_isos)/TinyCore/TinyCore-7.2.iso bs=128K of=/dev/sdx oflag=direct
and to clear the partition table
dd bs=1 count=64 if=/dev/zero of=/dev/sdx seek=446
This left the isolinux code in the first 440 bytes of the MBR as well as the disk label from offset 440 - 446, the partition record and the MBR identifier in the last 2 bytes
To set the first data sector on the HDD to sector 4, give it the remainder of the first 16 cylinders, mark it as a hidden partition and to set it active ( bootable),
Using sfdisk from a command prompt in KNOPPIX I issued
sfdisk -N 4 -u S /dev/sdx
4 32764 17 *
I was amused when sfdisk gave some warnings pertaining to DOS
<ignored>... eh blah blah .. zero the first sector ... blah blah . </ignored>
This starts the 4th partition at offset 2048 or the 4th 512 Byte sector. It gives it the remainder of the 16 cylinders or sectors 4 through 32768 for a size of 32764 sectors for the iso9660 fs. Partition #4 can be mounted as an iso that is read only. It is also set active to be bootable and is not visible to most applications in Windows.
This satisfied booting from the iso. It doesn't try to grab the entire usb disk anymore when accessing /mnt/sd?/cde. Now it finds cde at /mnt/sdx4/cde and I can mount and umount the rest of the partitions without hassle.
While back in TC-7.2 , using fdisk from there I was able to create 2 more partitions at /dev/sdx1 and /dev/sdx3
Partition1 was the next so many cylinders leaving room for a small partition at the end.
This satisfied Windows that it was now the first partition on the disk and it was happy . It can read and write to it.
My portable files can be transferred to and from there and they are good to go.
The last partition is for a tce directory and have a bit of room for any mydata.tcz or stray executables and scripts. And Now it is good too.
After creating filesystems on the device partitions. I can now boot freely between TC-7.2 on the usb stick and Windows on the internal HDD. Windows can do what it wants with the large partition there and those files are available to me when I need them.
When I need TC, I have a much more powerful command set at my finger tips , it's there.
If I just want to carry some files with me between computers or to a computer off the grid I have them with me on the same stick.
If someone starts mucking about deleting/editing files in the Fat32 partition They haven't really gone away. Just hiding waiting for photorec to get them back.
The trickiest part was to write back an isolinux.cfg file to the ro isofs located on the usbstick.
But hexdump and dd are friends of mine and were up to the task to cure that woe of mine.
After trimming the descriptions a bit , 1445 bytes was enough room to add consoleblank=0 multivt and waitusb=15 to core-w.
Life IS Good !