Pitot Tubes on Chinese MiG-21 Derivatives

Does anybody know which of the various Master MiG-21 pitot tubes would be the “best match” for Chinese variants, like the F-7B or F-7GS? I’m planning to do the Trumpeter 1/48th J-7B as a Bangladesh Air Force F-7MB, and a Sri Lankan F-7GS, and while Master does different pitots for many MiG-21 versions, the Chinese aircraft have their pitots on top of the nose, slightly offset, as against the undernose pitot that’s used by the MiG-21F-13 (which is the closest Soviet MiG-21 to the F-7B, at least), and it’s difficult to judge whether the pitots are longer, as on the MiG21F-13, or the shorter type from the MiG-21UM.

Does anybody gave definitive information? I’m veering towards just picking up a couple of MiG-21UM pitot tubes, since they’re at least meant to be in the right position, even if they end up being a bit short.