More than a rectifier, it seems to be a voltage regulator or stabylizer, based on luminiscent discharge as voltage reference.
The cathode structure of this lamp seems to be the same as in regular glow lamps for signaling purposes, as in Osram "glimmlampes", but the anode shows a more sturdy constitution, where clearly can be seen that these kind of lamps have been purposely polarized to DC operation.
This is, at least, I'm guessing about such a lamp, because I haven't any info about, but this seems clearly to be a voltage reference tube, like the 150B2, the 85A2, the OD3... and so, but fitted with Edison E27 cap instead any one of the usual types of multipin bases used for valve connection.
Regards.
