Non-Inverting Tri-State buffer with transistors only possible?
Your linked circuit shows what is essentially a 74125 buffer on the left side.
TI's SN74125/126 datasheet shows how the TTL tri-state buffers are implemented (the only difference between '125 and '126 is the polarity of the tri-state input):



(TTL chips used only NPN transistors, so the output cannot go up VCC.)