This Mullard PL83 was made in Holland by the parent company Philips. The groove in the join between the hard glass base and the soft glass envelope is typical of Philips machinery.
The PL83 was designed as a sensitive video amplifier valve for television receivers.
The discolouration of the inside of the glass testifies to the hard service life it has seen. All three wire grids can be seen through the hole in the anode.
The construction uses quite thick mica sheets top and bottom. Note also the screens at top and bottom.
The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 69 mm tall.
References: Data-sheet & 1040. Type PL83 was first introduced in 1951. See also1951 adverts.