I wouldn't bother to make a part to match his part, you'll have plenty of chances to practice making parts if you use DipTrace for anything else.
PCB schematic capture and layout has gotten a LOT easier over the years. I used to do the PCB layout with tape, talk about a PITA, and changes were a nightmare! Here's a page that describes the process, it was not pretty! PCB Design, a Graphic Artist's Handicraft by Skilled Designers. Checking the tape job was a very tedious task for large boards, and if you weren't REALLY careful with the taped mylars, you'd lose a trace or two. You had to create all the top and bottom layers and have perfect registration between them. Your best friend was the light table.
After you finally got the taped mylar design verified, you got films made. You had a whole stack of films, one for each layer, both silkscreens, both solder masks (if different), all the copper layers (depending on the number of board layers, etc. This whole bundle got shipped to the PCB house to actually create the boards.
Not to worry about the TMCC Buffer, as soon as I get the SMT boards in and test that layout, I'll be sending out the group email for everyone, then they'll have to commit with real cash to be in on the order. This is a BTO process, and it'll be a one-time deal, I'm not planning on making the buffers a long term thing. I'll be doing the board and assembly order from one of the Chinese houses I use, and I have to have a decent quantity to do a build at a reasonable price. There are also several $10+ parts in the design that I'll have to source, as well as the plastic enclosure and power module. I have everything figured out as far as production, and I've even built a simple assembly jig to drop the completed boards from China on to add the thru-hole parts with the proper spacing.
I suspect once the initial demand is satisfied, there'd be very few additional orders. I never expected this to be a cash cow, I just made a commitment to Dale about doing the build. Even though he's gone, I felt it was only right that his legacy be carried forward, he did the heavy lifting on the project. Also, I'm sure that some people that get them will later decide they don't really need them, so there's bound to be a "used market" after a time.