Smart and Brown 1024s had one. At least mine did have one. I've looked high and low for it. I'm beginning to suspect it found its way into the coolant tank . The good news is that I plan to change over to Castrol Alusol A in the near future so fingers crossed it will turn up. Otherwise I will be looking for a photo of one.
Your photo reminds me of the eye dropper or pipette made of glass with rubber bulb for drawing in and expelling drops; too vulnerable for lathe use but a useful idea.
The old Holbrook also has a relieving setup. The manual explains , this is for making things like taps, hobs and spiral reamers. The old lathe weighs in at 1400 Kg.