I searched the Bentley site via MIRLYN for “diner” and for each of the names of the diners, and the addresses, but, strangely, did not find anything. I did the same for the AADL photo database. The AADL had a few diners’ pictures, but not the ones you seek.

However,
Swede’s diner, with a cool interior photo, is covered in this website: [link] which is run by Jim Rees. Perhaps he can send you a copy of that photo; his email is jim.rees at the domain rees.org.

He also has a pic of the Dagwood (now Fleetwood as you know) here: [link] (scroll down)

Rees also has a photo of a Dagwood Diner matchbook: [link]
He also says that the current owners are George Fotiadis and Adi Demiri. Perhaps these folks can be contacted to see if they have additional Dagwood memorabilia.

I did not find photos of any of the other diners. If it were me, my next step would be to find historic photos of the streets in question. However, a search for that section of 5th ave. in both the Bentley and AADL yielded no photo that includes the diners.
A table including several of the diners you’re interested in appears here: [link]; no photos, but start/end dates & owners.

Not terribly helpful, but I hope you find more info.

Sperry’s Diner 210 5th Ave
Fifth Ave Diner 210 5th Ave
Swede’s Diner 210 5th Ave
Ward’s Diner 210 5th Ave
Dagwood Diner 300 S Ashley

(these would be similar in looks to the Fleetwood~a prefabricated structure and from the 1930′s)

Hint time: Despite a lot of thoughtful and creative guesses, I will say that thus far, the correct identity of this object has not yet been mentioned in the above comments. Also: this item may be found in the Ypsilanti Historical Museum’s second-floor “tool room,” in which may be found things like an old portable carpenter’s toolbox, sad irons, seed planters, old wrenches, &c. (one of my favorite rooms). :)

It looks like the thing we used to hold our kite sting in our hands with as a child. String was tied in a loop and we wound the string around it as we realed in the kite.

Regarding Pontiac Trail, there was a hotel there in the 1860′s named the Kusseth House, at the intersection of Summit (there is no Summit now, probably renamed later); which leads me to the question of whether any readers have information about that beautiful old civil war era hotel on Pontiac Trail in South Lyon. It features a wide porch with columns on both the 1st and 2nd floors wrapping around the building — which appear to be copied on some modern housing just to the north if it.