You had 2 different models of Motobomba FFF ( FFF = initials of the inventors, col. pilot Prospero Freri, engineer of the Air Force col. Amedeo Fiore, designer capt. Filpa)
1) MOTOBOMBA FFF CON CARICA DA 120 KG
German Name: Lt. 350
Weight: 350 kg
Dimensions: 500 mm diameter x 2,6 m length
Charge: 120 kg.
Range: 15 km
Speed initial: 13,5 Knots
Final: 3,9 knots
2) MOTOBOMBA FFF CON CARICA DA 90 KG
German name: Lt 280
Weight: 280 kg
Dimensions: 500 mm diameter x 2,60 m length
Charge: 90 kg
Range: 12 km
Speed: Initial: 13,5 knots
Final: 3,9 knots
Apparently it used the same body as the Motobomba FFF of 350/120kg but had a smaller weight therefore could be used on monoplace fighter bombers such as the Regianne 2002 .
It was tested by the Germans, giving it the designation LT280, but not adopted by them.
Details of is use by the Italians are unknown - probably did not go farther than the operational testing stage.
This is the original German publication on the fuzing of the LT350:
Abwurfmunition-Torpedos - Munitions-Handbuch -Heft 3f - Flugzeugtorpedo LT 350 - Beschreibung und Bedienung der Gefechtspistolen
The problem is that the Italians were very creative in the field of air dropped torpedoes and during ww2 produced a wide range of model of small torpedoes, some with circling course like the motobomba, that were often tested operationally but not produced - in teh Italian archives I found mention of the folowing "silurotti" designed for air-droppimng (other "silurotti" were desisgned for the MAS fast torpedo boats)
Siluro G. R. (Crocchi) su velivolo P. 108 1943
Siluro WA130 da 450mm su Fiat G55
Silurotto W 250/450/4,40 840 kg
Siluro CNA. 125/450/3,63 530kg
Silurotti W 200/450/3.38 650kg
Silurotto SB 120/450/3,18 580kg
On most of these there is no data presntly available .