Free Spirit "Brittany Te12" Part Identification/Upgrade i found this old 12 speed basically attached to a neighbor's back porch by vines, and aside from some superficial rust on the chrome, it seems to be structurally intact. the decals read as stated in the title and also indicate that it was sold by Sears Roebuck and made in Taiwan.
a photo album of the bicycle and closeups of parts is available here.
i can't find any reliable documentation specifying the parts currently installed, but as far as i can tell from googling, it appears to have:

a very noisy, threaded, adjustable cup-and-cone BB. resource
a cottered crank, which was loose, and upon tightening, became crooked. resource
a &quot;Falcon XT&quot; rear derailleur with little remaining spring tension.
a &quot;Falcon&quot; front derailleur with little remaining spring tension.
a 126QR bolt-on, drop-out rear hub, based off of ~126mm measurement. resource
a bolt-on, drop-out front hub that i could not identify (nothing found with ~88mm measurement).

i would like to replace most of these with modern equivalents that fit with minimal/no modification. (e.g., a non-cottered crank, quick-release hubs, common derailleurs, etc.)
the only resource i could find with something specific was this Reddit post where someone claimed to replace the BB with a Shimano UN-55.
tl;dr: knowing the parts is useless. You have a caliper, now you just need to remove everything and measure everything. You will learn something just by disassembling this bicycle and not focusing on brands, just on dimensions and &quot;mechanics&quot; of the parts you are removing.
Then, about reassembling it, it will cost you 5 times the money and 50 times the time+effort with respect to a bicycle shop.
Disclaimer: I do not own a bicycle shop.

The parts currently installed have no value and will provide very little information on their own.
You can still disassemble them and try to understand a thing or two on how they are assembled and maybe how they work, especially about the derailleur (springs, limiting screws and so on).
Bottom bracket and cranks are good to be recycled (=scrap metal), as well as the chain and whatever is installed on the rear wheel as a cassette.
New bottom bracket and crank ---&gt; most likely new chain line. Which is not that bad considering that the wheels will almost for sure need a good clean (greasing the hubs and so on) and you may discover that they are in bad conditions, so counting them temporarily as scrap metal as well, the new chain line is less of an issue (you have a lot of freedom once you have to replace bottom bracket, crank, rear wheel).
So remove the bottom bracket, check whatever size is relevant.
Then check the fork. Remove it, give it a thorough clean and a good examination, check for cracks in the fork or for deep rust. You do not want a fork that breaks in half while sprinting across an intersection, nor while you are just coming up/down from the curbs.
Check and note wheels size.
Save the frame, maybe the fork, then you have a lot of freedom in how to reassemble this bicycle.
I forecast something on the order of at least 3/400 USD/EUR/GBP, only for the parts (assuming you have all the needed tools for cassette, bottom bracket, fork, etcetc).