Thanks to RyanSem, houndsbourgh, Senex Bibax, Stevegeo, Dj4822, Dave (davidmcgo), Ann (artemis.sleeps), Dave Trott and daltons for your contributions which, as ever, are gratefully received. I've entered all the details into the C90 Registry which is now at edition 3.
I'm intriged by the extra numbers on RyanSem's corrector - that's the second instance reported of a C90 having more than one number as Jim (ftwskies) has two numbers on his C90.
houndsbourgh - yours is the earliest serial number for the new gloss black style on the C90 Registry - best I can do for a date is to say it must be some time after late 1984. In the S&T Sept 1984 issue on page 249 there was an advert headed "Celestron Close Up News Notes" which stated:
"New Colors. Celestron’s complete line up of Refractor, Newtonian and catadioptric telescopes is sporting a striking high-tech black tube trimmed in Celestron orange accents. See your local dealer for an introduction to the new Celestron colors!"
I'm guessing that this is when the C90 changed to the gloss black style with the ribbed rubber focusing ring and the screw-on metal dew shield. The Celestron double page ad in S&T in November 1984 (page 438-439) includes a gloss black C90 with ribbed rubber focus ring and screw-on dew shield.
Ann - thanks for the details about the accessories that came with your scope, mine (Spotter s/n 903937 so slightly earlier than yours) came with the accessories in a small blue cardboard box with styrofoam insert with no label and with a single 18mm 0.96" Kellner marked (KD) for Dai-ichi Kogaku Co Ltd (and which still has its Japanese Telescope Institute Inspection sticker), Celestron Star Diagonal 0.96" Japan and a 2.5x Celestron Barlow Lens 0.96" Japan.
houndsbough & wfj - when I got my Astro the focusing was very rough and scratchy - after cleaning the old grease off I also had quite a bit of lateral play in the threads - using Super Lube (synthetic grease with PTFE) helped a lot - any thoughts about outgassing or any other issues with Super Lube? Whilst it has made the focusing much smoother it is rather stiff so I may have a think about using something else.
Stevegeo, have you had any luck with getting the details for your daughter's C90?
Dj4822, looks like quite a clean-up job there, how did it go?
Please keep the details and pictures coming along for the C90 Registry, many thanks.
Edited to add manufacturer for the (KD) mark - see Galakuma's post here.
Edited by Masvingo, 23 June 2019 - 03:39 PM.