Link assist:
https://drive.google.com/drive/folde...K-?usp=sharing
In what way do you think you've bitten off more than you can chew?
Freewheel is basically an all-in one gear unit that threads onto the rear hub. What you show for wheels is not a freewheel, there's a cassette that slides onto the splined provision on the hub. It may or may not be compatible with your setup. You need to attempt mounting both wheels on the bike to ensure they fit between the fork ends and rear dropouts, respectively. Spacing on newer wheels often isn't the same as what older frames used.
You've got good bones to work with here. The most important thing you'll need to do will be re-packing the grease in the headset and bottom bracket. To remove the crank, you'll need a cotter press. I've got a post somewhere on here about how you can upgrade to a non-cottered crank with these old Peugeots. Basically it's all about proper spindle selection, swapping the cottered spindle out for a non-cottered spindle, then selecting an appropriate cotterless crank.
OR go the easy, more expensive way, and get a proper-width French- or Swiss-thread sealed bottom bracket from VeloOrange or similar. I suspect that bike would be French thread, but it's in that potential year range (mid-late 70s) where some things were being products with Swiss threads.
Note that your lowest cost path with refurb is to keep the stock headset, stock stem, and the stock bottom bracket cups. They'll be metric, "French" threaded. There are options out there to upgrade to newer, but none are low-cost. VeloOrange has a lot of products. If you have a bicycle co-op near you, they may be able to help press-out the cotters so you can repack the bottom end, then properly press the cotters back in, if not mangled from pressing out.
The Simplex shifters, note that a lot of cables out there have lead ends that are too fat and will jam into the levers. On Amazon, the Schwinn recabling kit that costs like $12 actually fits them well, and will have everything you need to do the brakes and shifters. Search Amazon for this text: B00L8NDVD6
The Simplex derailleurs this may or may not have come with will have Delrin plastic parts with a penchant for fading and cracking. For derailleurs, it's probably best to replace them. You'll need to pick something compatible with its shifters, and that will work with whatever cassette you plan to slap on the rear hub. May be harder than it sounds. Most people will go with a vintage wheelset, and use bulletproof Suntour or Shimano/Crane front/rear mechs to tie it all together. Huret is always a good option, the 'Club' series works well.
Fortunately, it's friction shift, not index shift, so you have a lot of fudge room on how to piece it together if you have a fundamental understanding of things.
I may not be back on the forum for a few days to answer this, but hopefully it's enough to get you started. Just happened to see this sitting in the main feed and it's a topic I have a lot of direct experience with
