Baffling rear shock size

Hi folks, so for my University project I require my bike to have a compression damping or lockout switch, on both front and rear. My rear shock only has rebound, so I'm looking to replace it for something used. However, I'm left confounded by its size.

It's this exact shock: SR Suntour Epixon R Rear Air Shock - GritStone Cycles allegedly 197mm eye to eye,

With the closest one on Suntour's page being this: Details - SR SUNTOUR Cycling available in 200mm.

However, measuring it myself I get a stroke of 49mm, and an eye to eye of 203mm. The frame itself can compress its eye to eye roughly 60mm without a shock before it bottoms out. I have triple checked now.

I just wanted to know if I'm doing anything wrong; I'm measuring from the o-ring (a zip tie in my case) when the shock's been fully compressed to the seal, and I'm measuring from the centre of each eye. Under full compression there's still 7+mm left on the stanchion.

What's more confusing is the sliver of information about my bike. It's a 2015 Voodoo Canzo, with 140mm of travel, yet on the site for the current Canzo and BeBop (same frames, same as my 2015 but with a tapered head tube too I'm fairly sure), the site mentions 140, 130, and 120 mm of travel, all with a 200x51mm shock!

What d'you reckon's the true shock size? I don't mind picking a shock that's slightly shorter since all it'll do is slacken the bike, but I do want to maintain it's current travel (whatever it is! :P)

Thanks!