Thank you everyone, I've learned a lot!

From the inputs here, and my own research, I now have a simple plan.

I will not use a regulator. The brass touch heads are already
regulated it seems.
The torch head on the old type I've got unscrew at the air holes, so
I'll just hook up a rubber tube directly to that somehow. I mic'ed
the threads there, they look like a 7/16 - 28 UNEF, or even a 32?
Whatever, I'll be able to make some type of connection there, even if
it's just a hose clamp.

With luck I'll be fireing the old hand-grenade up this weekend. Will
report back here if it works or not. Will also take some pics if there
is any interest.

Thanks again,
PaulS