Here I present the dates of my first documented/logged observations for all 110 Messier objects, all observed with my 110 mm f/24.7 Schiefspiegler.
M1 1974 Mar 20 M2 1976 Aug 22 M3 1974 Apr 13 M4 1974 Jul 5 M5 1975 Jun 6 M6 1976 Aug 23 M7 1976 Aug 23 M8 1975 Jul 13 M9 1976 Jun 17 M10 1975 Jun 6 M11 1974 Jul 12 M12 1975 Jun 6 M13 1973 Sep 3 M14 1976 Jun 17 M15 1974 Jul 28 M16 1974 Jul 12 M17 1975 Aug 6 B 1975 Aug 7 M18 1975 Aug 7 M19 1975 Jul 3 M20 1975 Jul 13 M21 1975 Jul 13 M22 1976 Aug 23 M23 1986 Jun 29 M24 1975 Jul 13 M25 1975 Aug 7 M26 1974 Jul 12 M27 1974 Jul 2 M28 1976 Aug 22 M29 1976 Aug 22 M30 1976 Aug 22 M31 1973 Sep 3 M32 1973 Sep 3 M33 1975 Aug 6 B 1975 Nov 10 M34 1974 Dec 13 M35 1973 Nov 21 M36 1973 Nov 17 M37 1973 Nov 21 M38 1973 Nov 23 M39 1974 Jun 3 M40 1982 Apr 10 M41 1974 Mar 24 M42 1973 Dec 12 M43 1973 Dec 12 M44 1974 Feb 10 M45 1973 Sep 2 M46 1976 Mar 20 M47 1976 Mar 20 M48 1976 Mar 21 M49 1976 Apr 6 M50 1976 Mar 20 M51 1974 Jun 6 ? 1974 Aug 16 M52 1974 Feb 10 M53 1975 Apr 28 M54 1986 Jun 29 M55 1986 Jul 15 ? 1986 Jul 29 M56 1976 Jun 17 M57 1973 Sep 3 M58 1976 Apr 6 M59 1976 Apr 6 M60 1976 Apr 6 M61 1976 Apr 6 M62 1975 Jul 3 M63 1976 Mar 21 M64 1975 Apr 28 M65 1975 May 16 M66 1975 May 16 M67 1974 Feb 10 M68 1976 May 16 ? 1982 Apr 19 M69 1986 Jun 29 M70 1986 Jul 1 ? 1986 Jul 16 M71 1975 Aug 6 M72 1976 Aug 22 M73 1976 Aug 22 M74 1976 Oct 26 M75 1986 Jul 3 M76 1976 Jan 7 M77 1976 Oct 26 ? 1977 Feb 13 M78 1976 Jan 18 M79 1975 Jan 8 M80 1975 Jul 3 M81 1974 May 26 M82 1974 May 26 M83 1983 May 15 M84 1976 Apr 5 M85 1975 May 1 M86 1976 Apr 5 M87 1976 Apr 5 M88 1976 Apr 3 M89 1976 Apr 6 M90 1984 Apr 25 (prob 1976) M91 1976 Apr 3 M92 1974 Apr 19 M93 1976 Mar 20 M94 1975 Jun 7 M95 1975 Feb 4 ? 1976 Mar 21 M96 1975 Feb 4 ? 1976 Mar 21 M97 1976 Mar 21 M98 1976 Mar 30 ? 1976 Apr 3 M99 1976 Mar 30 ? 1976 Apr 4 M100 1976 Apr 3 M101 1975 Apr 28 M102 (NGC 5866) 1976 Mar 21 M103 1973 Dec 18 M104 1975 May 1 M105 1976 Mar 21 M106 1976 Mar 21 M107 1975 Jul 3 M108 1976 Mar 21 M109 1976 Mar 21 M110 1975 Nov 10
Doubty first observations are marked with a "?", those with binoculars which I found documented with a "B"; in these cases, I also give the date of first safe observation with the Schief.
Actually I don't know when I observed the first Messier object first (probably somewhen around 1970), but with my Schiefspiegler, I first observed the Pleiades M45 on September 2, 1973. The last Messier object, M55, was eventually observed with the Schiefspiegler in the night of July 28-29, 1986, which completed my almost 13-year observation series. Since, I've observed all of them again for several times.