  We present the analysis of archival Very Large Telescope (VLT) MUSE and
multi-epoch Hubble Space Telescope (HST) WFPC2 and WFC3/UVIS narrow-band
observations of the remnant associated with the ejecta of the mid-nineteenth
century outburst of the recurrent nova T Pyx. These data sets are used to
investigate its true 3D physical structure and the nebular expansion patterns
along the line of sight and on the plane of the sky. The VLT MUSE emission line
maps and 3D visualisations based on position-position-velocity diagrams reveal
T Pyx as a bipolar nebula, with a knotty toroidal structure at its waist best
seen in H$\beta$ and two open bowl-shaped bipolar lobes (a diabolo) best
revealed by the [OIII] emission lines. The comparison of multi-epoch HST WFPC2
and WFC3/UVIS narrow-band images and VLT MUSE emission line maps of T Pyx
reveals the angular expansion of the remnant through the proper motion of
individual knots and nebular features. The angular expansion is confirmed to be
homologous in the period from 1994.2 to 2007.4 before the recent 2011 outburst,
but there is suggestive evidence that the inner knots have experienced a higher
expansion rate since then.
