I got the Fotodiox leather strap from Amazon and it does NOT fit my Rolleiflex, although my model is listed in the sales blurb. The metal part is way too thick to go through the stays on the camera. I would not recommend this product for a Rolleiflex T.
I'm starting to avoid/replace leather straps on vintage cameras, after having three different older leather straps break while carrying cameras (original leather straps riveted to Rollei Eveready cases). Generally I like classic period gear, but in this case I'm willing to go synthetic for more reliable strength characteristics. I like the OpTech Pro straps; all synthetic, strong, easy to clip on and off.