Well, all the ones I've painted so far - I've still got the Observation corps and a few more converged grenadier regiments to do, but all of the line regiments that fought during the Seven Years War are now painted.
Anyway, if you want to know what 39 regiments of infantry look like together:
Of course, I forgot to include something to indicate scale - the block is 42cm (16.5") wide by 27cm (10.6") deep; they would just about fill a sheet of A3 paper.
Working left to right, the regiments are:
Front Row - converged grenadiers, converged grenadiers, 1st Grenadiers, 2nd Grenadiers, 3rd Grenadiers, 4th Grenadiers, Apsheronskiy, Arkhangelogordskiy, Astrakhanskiy, Azovskiy, Butyrskiy, Kievskiy,
Middle Row - 2nd Moskowskiy, Muromskiy, Narvskiy, Nevskiy, Pskovskiy, Riazanskiy, Sankt Peterburgskiy, Sibyrskiy, Smolenskiy, Suzdalskiy, Troitskiy, Viatskiy, Vornonezhskiy
Back Row - Bjeloserskiy, Kazanskiy, Kegsgolmskiy, Ladogaskiy, Nizhegorodskiy, Nizovskiy, Novgorodskiy, Permskiy, Rostovskiy, Schlusselburgskiy, Tchernigovskiy, Uglitskiy, Vologdaskiy, Vyborgskiy
All the figures are 15mm from Essex Miniatures with cast-on flags that had to be hand-painted (not easy to do so the regimental symbols are somewhat impressionistic).
For the Observation Corps, I still haven't decided whether to go with actual Obs. Corps figures in the dragoon boots, or to stick with Essex and paint the gaiters as if they were dragoon boots. It does depend on the figures - Blue Moon and Old Glory 15s are much larger than the Essex so wouldn't fit in so well; Irregular are about right for size but rather "Meh!". I'll probably stick with Essex; the other advantage with doing that is that I know the figures, so won't have to make any changes to my painting.