WE mostly made unique designs and seldom made a version of some other manufacturer's design. 2A3 was an RCA invention, originally a single plate tube with a proportionately higher plate impedance than the later biplate 2A3, thus creating difficulties in designing an amp to use either variant. WE made the WE275, which has more or less biplate 2A3 operating specs but has a 5V filament rather than 2.5V. So you're going to need a 300B amp to run a WE275 in order to get close to creating a "WE 2A3 amp", or to modify a 2A3 amp designed for biplate 2A3s by changing to a 5V filament supply. Yup, it gets very confusing.
FWIW Psvane makes a supposed 'WE275 type' tube with a 2.5V filament. For me this is the same crime as all of the '300B' variants made in the past that had different specs than a WE300B like higher plate dissipation and higher filament current and voltage. If it is a different tube, just naming it the same does not make it any closer.