Adding mids to a Harbinger 1.5?

[The Rotagilla]

Hey guys,

I've done a 1:1 build of a dual strip Univibe I have and while I've gotten it dialed in, the original unit has these mids to it that I'm going to attribute to component drift and I can't seem to replicate them. I've traced the original unit twice to be sure there were no odd values, etc. and everything is as it should be, so I'm hoping someone has some suggestions.

Thanks.