Here's a rough outline...
October 9, 1941: RAF flies first combat mission with the Airacobra I (export model of P-39C/D) strafing barges.
On December 7, 1941 five full Fighter Groups of P-39Ds are in service in USA.
April 30, 1942, first recorded combat between Japanese aircraft and P-39Ds occurs near Port Moresby.
May 15, 1942 marks the combat debut of Soviet "Kobras", these being Airacobra I types, supplemented almost immediately with P-39Ds ferried in via Iran.
Mid October 1943, P-39Q-5 is issued to 35th FG, flying combat missions from New Guinea. Meanwhile, P-39Q-1 fighters have been operating from Guadalcanal since early October, mainly with the 72nd FS. Their first significant combat occurs on October 30th, when 12 P-39Qs strafe ships and barges in Tonoki harbor, Bougainville.
November 1943, the Soviets begin issuing P-39Qs to front line units.
Per the Sherman Firefly: First issued to Brit tank units in May of 1944. These didn't get to the ETO until June.
Thus:
Theatres of Operations:
PTO - Pacific
ETO - Europe
CBI - China-Burma-India
EF - Eastern Front
Aircraft
USA
A-20G ... 5-42
B-17G ... 6-43
B-24J ... 5-43
B-26B ... 5-42
C-47A ... 12-41
P-38G ... 11-42
P-38J ... 12-43(ETO) 2-44(PTO)
P-38L ... 7-44
P-38D... 10-41 (ETO) 4-42 (PTO) 5-42 (EF)
P-39Q... 10-43 (PTO) 11-43 (EF) 1-44 (MTO)
P-40B ... 1-41
P-40E ... 8-41
P-47D-11 ... 3-43(D5) to 1-44(D11)
P-47D-25 ... 5-44
P-47D-40 ... 1-45(ETO)
P-47N ... 6-45
P-51B ... 12-43(ETO),8-44(CBI)
P51D ... 5-44(ETO),1-45(CBI&PTO)
F4F-4 ... 9-41(ETO),5-42(PTO)
FM-2 ... 6-44(ETO),10-44(PTO)
F6F-5 ... 7-44
F4U-1 ... 2-43(ETO),4-44(ETO)
F4U-1D ... 4-44
F4U-1C ... 4-45
F4U-4 ... 4-45
F6F-5 ... 7-44
SBD-5 ... 5-43
TBM-3 ... 2-43
Britain
Boston MK III ... 5-41
Hurricane Mk I ... 5-40
Hurricane IIC ... 4-41
Hurricane IID ... 6-42
Lancaster III ... 3-42
Mosquito Mk VI ... 7-43(ETO),11-43(PTO&CBI)
Spitfire Mk IA ... 8-40
Seafire IIC ... 10-42,11-43(ETO)
Spitfire V ... 4-41
Spitfire VIII ... 7-43
Spitfire Mk IX ... 7-42
Spitfire Mk XIV ... 5-44,7-45(CBI)
Spitfire Mk XVI ... 7-44
Tempest V ... 6-44
Typhoon IB ... 6-43
USSR
Il-2 Type 3 ... 10-42
La-5FN ... 3-43
La-7 ... 6-44
Yak-9T ... 1-43
Yak-9U ... 7/8-44
Italy
C.202 ... 11-41
C.205 ... 1-43
Japan
A6M2 ... 7-40
A6M5b ... 8-43
B5N2 ... 7-40
D3A-1 ... 7-40
Ki-61 ... 6-43
Ki-84-la ... 8-44 (CBI),10-44(PTO)
Ki-67 ... 4-44
N1K2-J ... 1-45
Germany
Ar 234B ... 12-44
Bf 109E-4 ... 5-40
Bf 109F-4 ... 6-41
Bf 109G-2 ... 6-42
Bf 109G-6 ... 2-43
Bf 109G-14 ... 7-44
Bf 109K-4 ... 10-44
Bf 110C-4b ... 8-40
Bf 110G-2 ... 5-42
Fw 190A-5 ... 6-43
Fw 190A-8 ... 2-44
Fw 190D-9 ... 12-44
Fw 190F-8 ... 4-44
Ju 88A-4 ... 5-41
Me 262 ... 10-44
Me 163 ... 9-44
Ta 152H ... 1-45
Vehicles
USA
LVT(A)2 ...2-44
LVT(A)4 ...3-44
M-3 Halftrack...3-41
M-8 ...9-42
M-16 ...5-43
M4 Firefly... 6-44 (ETO)
Germany
Ostwind ... 8-44
Wirbelwind?
Panzer IV Type H ... 8-44
Tiger I ...8-42
Soviet
T-34/76 ... 2-43
My regards,
Widewing