From
Flight of March 22nd 1917 (just four days before his death) JB Fitzsimons is given as flying for F. Nestler Ltd; it appears from the wording of this article that the plane in which he was killed might have been a prototype and the first (and last?) that the company produced; the 2nd and 3rd articles gives details of the accident & inquest (note that a 2nd 'm' has been added to his surname), but not the type of plane involved. A search on Nestler indicates that the company may also have been involved in hangar construction (?)
http://www.flightglobal.com/pdfarchive/vie...arch=Fitzsimonshttp://www.flightglobal.com/pdfarchive/vie...rch=fitzsimmonshttp://www.flightglobal.com/pdfarchive/vie...rch=fitzsimmonsThere is, unfortunately, no mention of the accident or an obit. in
The TimesEDIT: searching back further in the
Flight Archive finds, in 1914, a 'JB Fitzsimons' (given as 'Hon. Sec.' of the 'Ilford Model Aero Club') inquiring about anemometers, as well as later references to his training, Aviator Certificate & military service
EDIT II: there seems to be very little information - at least on the web - about Nestler, but there is this:
http://www.aviastar.org/manufacturers/1545.html which gives that only one plane was ever produced by the company, and that it did crash in 1917; the same site even has a photograph of the Nestler 'Scout'
http://www.aviastar.org/air/england/nestler_scout.phpNigelS