SU-5 in third versions were produced in big number (in the comprasion to another prototypes 15 to 30 pices)
http://rkkaww2.armchairgeneral.com/w...tm#10.STriplex
So meaby beter is left them as front units because as we can read they wer intensive use on the front during campaign in poland in 1939 as i read in my book they fight in tank unit in the direction to Brest-Litvovsk and than in 1941 against germans during barbarossa. 11 of them was in 1941 on the Far East what sugesst they surrive first german wave and meaby last Su-5 were used last time during desperate days near Moscov?