Of the two known surviving Sanskrit manuscripts of the Sarvatathāgatatattvasaṃgraha, one has been published in facsimile by Lokesh Chandra and David Snellgrove in 1981. The other one is said to be written in late Gupta characters, and was in the collection of General Kesar Sham Sher Jang in 1932 when Giuseppe Tucci announced the discovery of it (Indo-Tibetica, vol. 1, p. 93). That collection should now be part of the Nepal National Archives, Kathmandu, and it would have been microfilmed by the Nepal-German Manuscript Preservation Project. However, I was unable to find it listed in the catalogue of the Nepalese-German Manuscript Cataloging Project. Does anyone have any more information about this manuscript, or a microfilm or scans of it (or even a microfilm or scans of the devanāgarī transcript of it that Tucci obtained, and that was used by Horiuchi for his edition)?
J. W. de Jong, in his 1977 review (Indo-Iranian Journal, vol. 19, pp. 125-127) of Horiuchi's 1974 edition of the second part of this text, says he checked Nagao's 1963 list of the Buddhist manuscripts in the collection of Field Marshall Kaiser. As reported by de Jong, this list does not mention the Sarvatathāgatatattvasaṃgraha, and the only manuscript there described as written in Gupta characters is entitled Sarvakula-tatvasiddhi-vidhi-vistara-tantra. I have also searched the catalogue of the Nepalese-German Manuscript Cataloging Project under that title, with no results.
Best regards,
David Reigle
Colorado, U.S.A.