Star Trek TOS style Oberth class

My interpretation of how the Oberth class would've looked in the original series, replacing bits with classic Constitution class parts, used a small part of the TOS Miranda on here to attach the engineering section, extended the engineering section with a smaller bit lined up to replicate the length, I thought it made it look like it could be switched out by leaving the squarish parts on the side. This one should be a bit more canon than my TOS Akira, since the ships were supposed to be around a