Useful for new module prototype development...
I think my first will be 8255 or Z80 PIO module.
---
BTW - if you want CTC module, I found complete PCB here: https://easyeda.com/sccousins/sc102-z80-ctc-v1-1-for-rc2014.
What was surprising for me: obtaining of Z80 CTC chip was not problem - it is possible to buy very easy many years after 8-bits era.... Nice :-)

The prototype PCB for RC2014 is a fine, high quality board that arrived quickly. As mentioned in the description, it contains 39 pins, not 40. The board is designed to allow easy wiring of dip style ICs by having some of the holes preconnected, as indicated on the PCB by the white markings, with two bus lines running the length of the board. This is great if you need to install up to three 20 pin ICs on the board, but not so good if you need to maximize the space. Overall, they are high quality, and arrived as described. Shipping was quick to the US.

The only problem I had is in finding the right-angled headers that are an EXACT match of the ones provided with the RC2014 kit. These headers are not provided with the PCB. The headers that I sourced from Digikey contain the plastic spacer on the wrong half of the header, which cause the boards to be slightly misaligned. I could not locate the EXACT header part at Mouser or Digikey. I found discussion about this problem in the forums, and people have gone with various solutions, but to my knowledge the US suppliers Digikey/Mouser do not supply an EXACT match for the headers supplied with the RC2014 kit.

In this case, it would be helpful if the Prototype PCB board came with headers that matched those included with the RC2014 kit, or if a part number for the EXACT header was listed in the description.

I was so happy when i got it as Christmas present , i have learn a lot , the computer work perfect after debugging about 2 days i recommend to improve the documentation witch exist online but is confusing and describe all the versions in one article and mix all together and the reader have to figure witch is apply for his item. Will be great to include a serial cable to connect with computer. i didn't finish yet the keyboard since i have limited time for my hobby. All in one is a great idea and i recommend to everyone witch want to better understand how computers work and how different parts is connected and work .

The board only connects to 39 of the RC2014 40 backplane signals. It is too narrow to accept the 40 pin header supplied. The missing signal connection is in the "SPAREx" signal group. So, if you do not need the last signal in this group, the board is still quite usable.

This is definitely a useful board to tidily bring out the connections you need for your own device, due to the small form factor of "standard" rc2014 boards the amount of circuitry you can get actually on this board is potentially quite limited, but never the less this is useful for your own experiments