You certainly are picking up on the details. The 15097, at least if the pictures are right, has the classic thimble tip on it. The dome with the slits. Both the 15733 and the 15738 have the later, square end with the small bulb on the tip. This leads me to believe that the 33 and 38 are probably the same or at least interchangeable, but who knows? I found the 38 for $67, which is now $20 less than the 097, so that's now at the edge of the "practical to solder yourself" range. Of course I've now put about $100 of time into the project at my preferred rate of $2.95 per hour (Volvo DIY/Internet/Brickboard hourly rate)--LOL.

Dave