Hi Al, Ken,
While a lurker on IceInSpace I'm sorry to say I wasn't aware of this spectroscopy forum ... until alerted to the possibility by Ken's posting on Spectro-L. Melbourne's inner city clouds lifted long enough last night for me to grab a 100s low-res slitless grism spectra ... copy attached. While I'm no expert on this star it does look as 'normal' as can be said for anything regarding this far from normal star. While Eta car does have regular HeII (4686A) variability I don't believe it is anywhere near as strong as your spectra shows, and I don't see it in my spectra (recorded with Sony chip which has good blue response). So I would agree with you in questioning if you imaged Eta Car ... I strongly doubt it. But top marks for trying, and keep up the effort as it needs more monitoring
Bernard Heathcote