I would try to over-seed with the same seed cultivars just for color consistency

That is going to be extremely difficult as o have no idea what cultivators are in my turf now.

Full rip and redo :-)

Heh. It would just drive me crazy is there were some spots that were lighter darker than others.

You do want to cut it short right before overseeding so it's not competing for light and such. personally, SS is $$ and may be worth it for a full on gut, but if to overseed without knowing whatca got, I'd just go grab from your big box store a bag of KBG of TTF / whatever is your preference for the blend.

I would not spend huge money on seed on an overseed without having a lawn with already "elite" cultivars present. Just get a bag of KBG and/or creeping red fescue if you have shade. Scotts kentucky bluegrass blend would be just fine. Are you overseeding because the lawn is thin? Every time I drive into Michigan, I am impressed by the lawns compared to Ohio.

Mishmosh - yes, I am overseeing mostly to make the turf more dense. The lawn has been neglected for 15 years and I have been trying to “get it back” over the last couple years now (into my 3rd). I eliminated a couple large areas in the spring that were 100% clover take over, so those areas are bare now. Plus some dog spots.

There are some areas that are real thin that I cannot seem to get to fill in with just Milorganite (maybe there is no KBG there??) so I am going to try to thicken those areas As well that have exlisting, thin turf.

I am tempted to do a full ren, but I don’t think I’m fully ready to attempt that with my skill level at this point. Maybe a year or two down the road I’ll redo with an elite blend.

GRS -

Your OP was not addressed but 6 weeks I would say would be after weed killer so skip the herbicide this year...so if manageable, just pull what you can, overseed and skip the herbicide for now. You are applying Pre-Emergent in the early spring right for mitigation yearly ? That's like half the battle every year on weed mitigation

I have not applied any pre-em, but I recently bought some prodiamine in preparation for next spring and the years to follow.

Sounds like your on the right course