Let me address a few things. . .
1. I need the column top flush with the DP head in order to install a column top pulley speed reducer (another thread for later).
2. I did think about going through the bottom, but I don't know what the stand looks like, i.e., if that is even possible. If so, the the table it is now sitting on is perfect as it already has a slot.
3. The table it is on was built to wrap around the standing DP. You cab see it in the photo below from my base build.
https://www.garagejournal.com/forum/threads/tanker-desk-to-drill-press-cabinet.465198/
4. I was thinking of a collar to be able to re-attach the cut post end. Probably out of my skill range, but not out of my gumption.
5. It does not make sense to me to spend time and effort to sell and then try and buy an equivalent bench model. Who knows what will be available. I got this DP at auction from an old factory across from my work. The factory formerly housed National Cash Register, and you can see that the DP was painted light brown the color of cash registers. It took me a couple of years to find this deal -- $135. Who knows what I could sell it for.
6. I admit it is a shame to cut the column. But I see no future need for the floor model, would probably be able to sell the bench top model easier to DIYers if it comes to that. After all, it is just a tool. . .gulp. . . that needs to work for me.