Imo's? Not any more. Provel (not Provolone) cheese and way overpriced. They used to actually put toppings on their pizza.
There are a few different routes through and around STL. Manchester Road (MO 100) is the original route out of town but these days it's nothing but stoplights and strip malls until well west of the city and reaching Gray Summit on I-44. But, taking this route bypasses all the bedroom communities along 66 (Watson Rd). There are still a few of the old motels along this route. The first diamond interview change was at Watson and Lindbergh and as mentioned before, Ted Drew's frozen custard (concrete) at the city limits that is so thick they turn the cup upside down to prove it.
In Pacific Main St. hasn't changed much. East of town the road follows the Frisco RR tracks, but most of the old motels are long gone. Jensen's Point overlook is still there as is the Red Cedar inn, a former roadhouse which operated until a few years ago, now it's a museum. Just west of there are the silica mines, still in operation. At Gray Summit is the Shaw Preserve, used by botanist Henry Shaw, who moved many plants from his research park in the city due to the soot and smoke from burning coal.
Don't miss Hooker Cut, once the largest rock cut in the country, made to expand and straighten 66 to bypass the narrow bridge at Devil's Elbow because Army vehicles going to and from Fort Leonard Wood couldn't navigate it. The Interstate that replaced the section through here is the last section of the Interstate completed in 1985 due to the steep hills and rock bluffs.
And, as mentioned, Uranus, MO, where the best fudge comes from Uranus. They use every Uranus pun you can think of. Lebanon, MO still has many old roadside businesses still standing. There is still a lot of 66 left west of here. West of Springfield 66 follows MO 96 through Joplin and then goes west through Webb City, Carthage and into Kansas, for its approximately 20 mile run through Kansas.
Rt66postcards.com is a good source for sites along the road, most long gone but there's still a lot to see.
BTW, the town of Miami, OK is pronounced, "Miamuh", just like Missouruh.
The "capsules" of the "elevators" of the Arch are actually considered trains, or trams and we're built by the old St. Louis Car Co, who built railroad cars and street trolleys.
Enjoy!