CptDondo wrote:
I have an old front door with a lockset that I can't for the life of
me get out.

It's an old Schlage - could date back 15 years or even more. It has
the key-in-knob lock.

The inside knob came off easily enough. But the outside knob will not
come off.

There's some sort of interlock between the latch (the part that
engages the door frame) and the square shaft that joins the knobs.

There's no apparent release mechanism, no visible screws, pins, etc.
holding it together.

The latch part will come out about 1/8" before it stops.

The outside knob will come out about 3/16" before it stops.

And the guts that the inside knob was attached to come out about 3/16"
before they stop.

After that it all seems to hit some kind of pin/interlock and nothing
will come out any further.

I could drill it out, but that would create a huge mess of filings. I'd
rather find a way to get it out sanely....

The outside knob does not come off. It is permantly attached to the rest of
the mechanism. When you remove the outside knob, all the guts of the lock
come with it. Therefore, figure out what's holding the main mechanical parts
to the door.