I have beaten every level and collected every gun in Hitman: Blood Money.Here is a list of the levels and weapon that can be found in the game.(note: the weapons collected on the level death of a showman do not count)
A vintage year-snub nosed, SAF SMG, TMP, and the Shotgun
Curtains down-MP5, SLP.40 pistol
Flatline-SLP.40 Pistol, TMP
A new life- SLP.40 Pistol, Bull.480, Air rifle
The murder of crows- Desert Eagle, SLP.40 Pistol, SLP.40S, MP9, SG552, KAZO TRG
You better watch out- SLP.40 Pistol, TMP
Death on the Mississippi- Desert Eagle, Snub nosed, Bull.480, shotgun, FN-2000
Til death do us part- Six shooter, shotgun, elephant rifle (elephant rifle is displayed on the wall)
A house of cards-SLP.40 pistol, SLP.40 S, TMP
A dance with the devil- Desert Eagle, SLP.40 pistol, MP7, MP5, FN-2000, Dragunov Sniper (the Dragunov Sniper is on the top floor where you check the computer it blends in with the desk)
Amendment XXV- Desert Eagle, SLP.40 Pistol, MP5, Custom 1911, M14
Requiem- SLP.40 pistol, MP7, Custom 1911
ENJOY!