Here is my pattern for the Tailstock. It's pretty much what is described in the book. The red stuff is spot putty that I used to make the fillets.
Here's the core. I tried making it using some Sodium Silicate that I had, but i could not get the core to remove from the mold. It kept breaking on me. After 5 unsuccessful tries, I gave up on the Sodium Silicate that I had. I think it was too old. I bought it about 10 years ago. So I tried using some slow setting epoxy. This worked out really well, but I wouldn't want to use this stuff all the time as it would get expensive.
Here's the mold all rammed up. It actually came out on the first try. You can see the core placed in the mold in the first picture.
This is what I saw when I opened up the mold. Looks good so far.
The casting came out perfect. You can see what's left of the core still in the casting. I wasn't sure how well the epoxy would hold up, but it looks like it worked well. It took me about 3 minutes with a punch and a hammer to remove the core. It came out as powder.
Some close-ups of the cored hole. It is nice and smooth inside.