When you look at period photo's, many of the wires and their connections are hard to see, even in fairly close-up pictures. So That would mean a very small wire and a very small turnbuckle...
well just to throw more flies in the ointment...
period photos are essential, obviously. but they can't tell you everything. (even if you've got an intuitive grasp of how orthochromatic film registers color; i sure don't).
i don't trust period photos to give me an accurate idea of how turnbuckles should look. why? quite a few reasons. most of the photos that i've seen are too contrasty. most of what i see are reproductions of reproductions. many are from (or in) books printed rather coarsely (benday dots FTW!). most i've seen are pretty beat up.
here's my philosophy of deciding how things should look on a model (i guarantee it's not for everyone): i try to imagine an ideal viewing distance... the 'main view.' then i figure out what the 'close up' view should be. and then at a distance.
i try to look at a real aircraft (or ship or boat or whatever, but here we're talking aircraft) from those distances. what do the details and even the colors, look like from your 'normal' distance to your naked eye? (in both cases you have to consider the lighting conditions, which is why i prefer outdoors to indoor museums). i would then want to document with photos, but i think it's important to get that impression first. when i see 'walkarounds' they are mostly useful but they tend to be obsessively close-in on minute details. which is great for noticing how a detail is put together, but people who rely entirely on this sort of observation (in photos or 'in real') are the ones who tend to be OK with things like panel lines that look like canyons or rib tapes like ridges.
it's not necessarily easy to find somewhere with vintage aircraft (restored or replicated full size) i know... not impossible, though. there are air museums all over the world with biplanes, even here in Thailand. but if you can't do that, i'd say modern photos of restored aircraft or flying replicas give a better idea of an answer to 'would i even see turnbuckles?' than period photos. a MUCH better answer, due to the relative condition of the photos and a few AHEM slight improvements in photographic technology.
others may have their own approach for deciding this stuff, this is just one. also, everyone who approaches it this way is NOT going to end up with the same opinion of what works. or same priorities for what a model should look like.
so far, i lean toward 1/48 turnbuckles for 1/32 aircraft, but the adult version of my obsession with WWI aircraft is very new. i got some lookin' to do.
