The availability of 8–10m telescopes now permit the routine observation of faint, heavily reddened peculiar emission line objects, which may provide new information on stellar evolution. One such object is NaSt1 (WR 122, IRAS 18497+0056), discovered by Nassau & Stephenson (1963) who proposed a WR classification because of its strong emission line spectrum. Massey & Conti (1983) identified NaSt1 as a peculiar WN10 star. However, subsequent work has argued against a genuine WR identification, favouring either B[e], O[e] or Ofpe/WN9 spectral types from optical and IR spectroscopy (e.g., van der Hucht et al. 1997). NaSt1 has recently received renewed attention, principally because it is extremely bright in the IR (K = 6.5 mag). Indeed, NaSt1 is currently used as a late WN-type IR spectral standard, despite its uncertain nature.