Glad someone is performing the "other" Czerny symphony in D, the 1814 one described at some length by Wyn-Jones in
The symphony in Beethoven's Vienna.
I believe there are or may be 7 or 8 Czerny symphonies (or more, as you mention)- 1806 movement, 1814 D major, no.1 in C minor op.780, no.2 in D major op.781, nos.3-6 unpublished at the time (but I believe later works. 5 in E-flat, 6 in G minor. 3 and 4 - not sure! May be being published now, though... soon? don't know.?)
Anyone have a copy of Wyn-Jones to hand? I've been going around and about and guessing with the Google Preview.

My area university library may have it. It contains info on a lot of contemporary symphonies, e.g. Krommer's 8-plus (that is, the 8 numbered surviving ones - well, not the sinfonias, he doesn't mention those, I think), Reicha's, and quite a few others as per his title.
(I think opp.780 and 781 postdate the D major 1814. Op.780 was performed in 1845 (and published in 1847 by Häslinger, likewise was op.781 - see
HMB@Rhul), it seems, so one knows -that- much- not later than 1845 for sym.1, publication date limit 1847 for sym.2; but how early, I don't know...)
At least according to
http://home.earthlink.net/~dbratman/syms_list.html symphony 3 is in C, symphony 4 in D minor, and all we have is "before 1854" (and Czerny having died in 1857 that's some information but not that much I suppose.) As to opus 2 being the 1806 symphony, doubly-applied opus numbers (and etc. and... ... ... ...) are, please pardon the double negative, not uncommon... the less-known the composer, it sometimes seems, the more hair-tearing the situation becomes. Just my observation. (With exceptions in both directions obviously...)