Memo (dated 1964-02-22) from Bofors regarding various possibilities in increasing the engine output of the S-tank. Options mentioned are a supercharged 275 or 300 HP version of the Rolls-Royce K-60 piston engine (a 240 HP version powered the first incarnation of the S-tank), a 300 HP Volvo piston engine in development for use on the pbv 302 APC and a Boeing 553 turbine.
Archive reference: SE/KrA/0266/005/01:H/F II/5
Original title: Teknisk bestämmelse för stridsvagn S, typ A
Incomplete; I only photoed the 60 or so pages I found most interesting (out of a total of 144). Dated 1964-10-04. Note the wax seal on the first page.
Archive reference: SE/KrA/0266/005/01:H/F II/5