There's a 50mph limit on the A726 eastbound from the M77 junction. A "50" sign can be seen in GSV at this MC. (NB there's also a NSL sign in the same location one month earlier.)

It extends to this NSL sign.

Per this UR "the speed limit here is now 50 for a small section for the sake of the new slip road before it returns to national speed limit".

There's some official blurb about it here.

GSV shows construction of slip roads for a new junction here. There's some info about it here.

Westbound, the limit drops to 50 here, and to 40 here.

Finally, the segments really could do with being re-aligned.
 
Thanks.