This is not a comprehensive list of all the axle parts, but I have covered most of the ones that you are likely to need. Early Jaguar XK120 cars had a very similar ENV axle, but with a narrower track, so unfortunately, their replacement half-shafts are too short. But Jaguar specialists might be able to help with some axle parts.
Hub bearings are ENV part number A254-63. Timken part number 25577/25522. Inside dia.=1.688" (42.88mm). Outside dia.=3.270" (83.06mm). Cone width=1.000" (25.40mm). Cup width=0.7525" (19.11mm). Width=0.940".
The hub bearing removed from my own axle were a slightly different part number, 25578/25522. These have an inside diameter 0.0005" smaller than part 25577/25522, and thus harder to press onto the axle. They are harder to obtain (at the time of writing, November 2014). 25577/25522 are the ones supplied by Jaguar specialists.
The differential bearings are listed by Jaguar suppliers (and other bearing suppliers) as identical to the hub bearings, but the AC handbook gives the part number M146-12. I haven't removed one to verify its dimensions.
I also have not verified the 2 bearings for the pinion shank, but believe them to be the following:
Pinion Head Bearing (Timken 3490/3420), ENV part number H108-40. Inside diameter = 1.5 inch, outside diameter = 3.125 inch, width = 1.1563 inch.
Pinion Shank Bearing (Timken 02475/02420), ENV part number H108/41. Inside diameter = 1.25 inch, outside diameter = 2.6875 inch, width = 0.875 inch.
Inner oil seal (hub): ENV part number A238-12 (marked with part number 237112-s). ID=1 3/8" (34.9mm). OD=2 3/8" (60.33mm). Thickness=1/2" (12.7mm). Single leather seal.
Outer oil seal (hub): ENV part number A254-22 (marked with part number 27520037). ID=2.000" (50.80mm). OD=2 3/4" (69.9mm). Thickness=0.375" (9.53mm). Single leather seal.
Differential oil seal: ENV part number H105-22. ID=1.75" (44.45mm). OD=2.875" (73.03mm). Thickness=5/8" (15.88mm). Double leather seal.
I've replaced my old leather seals with modern nitrile-rubber seals.
Axle spacer (this fits behind hub): ENV part number A250-16.
Ring nut for hub bearings: ENV part number A238-20. 1.689" (outside diameter of thread), 16TPI (Whitworth threadform), 2.22" across flats.
Keyed washer (for hub bearing): ENV part number A238-14. 0.109" thick.
Tab washer (for hub bearing): ENV part number A238-21. 0.047" thick.
Shims: ENV part number A238-10. Thicknesses include 0.006", 0.012" and 0.024".
Hub bolts: These are non-standard in length at 1 5/16" long (3/8BSF), high-tensile. I replaced mine with longer 1.5" long bolts, and fitted a washer under each of the self-locking nuts, to accommodate the increase in length.
The darker bolt above is an original rear hub bolt, flanked by a pair of standard length bolts (1.25" and 1.5" long).
Hub bearing housing: ENV part number A254-65 (Series 3 handbook states A254-5).
Differential housing: ENV part number H106-1.
Half shaft: ENV part number A250-11F embossed outside hub, and A248/11 stamped on edge of hub.
The following are all ENV part numbers.
Pinion adjusting shims: H105-38 and H105-39.
Diff. bearing adjuster locking tabs: NM119-34.
Crown wheel locking tabs: NM146-11.
Half-shaft thrust button: A238-11A.
Drive flange: NM121-23.
Dip-stick handle: H106-30.