Sometimes wishes do come true. No one in the record business has yet gotten around to giving us a new recording - or reissuing the old ones - of Vincent d'Indy's Second Symphony, Jaromir Weinberger's charming orchestral variations on "Under the Spreading Chestnut Tree" or Jean Francaix's still more charming ballet "Scula di ballo" (on themes by Boccherini), but Columbia has gladdened the hearts of many chamber music buffs with its release of all six Mozart viola quintets in much sought-after versions on its low-priced Odyssey label (Y3 35233, three mono discs).

In a column earlier this year (on Jan. 22) I mentioned in these pages that the Mozart cycle recorded by the Budapest Quartet with Milton Katims for Columbia just after World War II was "unforgettably effective, far more so, surely, than the Budapest's stereo remake with Walter Trampler." And the hope was expressed "that the five Mozart quintets recorded with Katims (they never got around to K. 174) will be available again some day."

That is just what the aforementioned Odyssey set contains - the five mature quintets by the Budapest with Katims, plus K. 174 from the later cycle with Trampler for the sake of completeness. The old recordings sound better then ever, K. 515 is now complete on a single side, and, all in all, this is something no one who is serious about chamber music should pass up, no matter how many duplications it may create in an existing collection.

The one flaw - and it is an incredible one - is that no one can tell what this set is by looking at it, for Katims' name is nowhere mentioned on the box. Only Trampler's name appears as the added violist, on both front and back of the container, and a further misleading impression is created by the listing of the Budapest personnel and the actual session dates for the Trampler recordings - all six of them - on the back-liner, together with the statement "previously released on M3L239" (the catalog number of the Trampler set).

Inside, on the disc labels', there is the correct information with Katims' name on five of the six sides - and also with the names of Edgar Ortenberg and Jac Gorodetzky as second violin in some of the quintets, in place of Alexander Schneider, who is erroneously listed on the back-liner as playing in all six. (Schneider is actually in only two of them - K. 174 and K. 516.) But the set comes sealed, of course, and the browsing customer in the record shop, unless forewarned, would have no way of knowing it is the Katims cycle that is in this mislabeled package.

Not exactly a reissue, but rather a reappearance in a different medium, is the open-reel tape edition of Kurt Masur's superb recording of the five symphonies of Mendelssohn with the Leipzig Gewandhaus Orchestra, the disc edition of which (Vanguard VCS-10133/6) was welcomed enthusiatically in The Washington Post on July 9.The tapes are being processed by the exceptionally quality-conscious Barclay-Crocker organization, and should be available now.

As every open-reel aficionado must know by now, Barclay-Crocker is the source for all recordings in this format - those from Stereotape, Total Sound and other processors as well as those processed from B-C itself, and from recordings issued on discs by Desmar, Halcyon, the Musical Heritage Society, Unicorn and Vanguard. (London's Argo and L'Oiseau-Lyre are to be added to this list before the year is out.) The company also publishes a comprehensive, periodically updated catalogue of all these offerings; it is available for $1, and monthly supplements are sent to purchasers. (Address: Barclay-Crocker, 11 Broadway, New York, N.Y. 10004.)