Copy the UI sections for each paint you want to install into your Seagull's Aircraft.cfg file, changing the X in the first line to the next number in sequence.

[fltsim.X]
title=Curtiss SOC-1 4-CS-9
sim=SOC-3
model=
panel=
sound=
texture=4CS9
kb_checklists=
prop_anim_ratio=-1.76
visual_damage=1
atc_id_color=0000000000
atc_airline=NAVY
atc_type=Seagull
atc-model=SOC
atc_id=4CS9
ui_manufacturer=Curtiss
ui_type=SOC Seagull
ui_variation=SOC-1, 4-CS-9, U.S. Navy
description=The Curtiss Seagull served the Navy well from 1935 to well into WW2. This one was flown by the leader of the 3rd or blue section of Cruiser Scouting Squadron Four, based aboard the heavy cruiser U.S.S. Pensacola in Cruiser Division Four in 1939.

[fltsim.X]
title=Curtiss SOC-1 7-CS-5
sim=SOC-3
model=
panel=
sound=
texture=7CS5
kb_checklists=
prop_anim_ratio=-1.76
visual_damage=1
atc_id_color=0000000000
atc_airline=NAVY
atc_type=Seagull
atc-model=SOC
atc_id=7CS5
ui_manufacturer=Curtiss
ui_type=SOC Seagull
ui_variation=SOC-1, 7-CS-5, U.S. Navy
description=The Curtiss Seagull served the Navy well from 1935 to well into WW2. This one was flown by the leader of the 2nd or white section of Cruiser Scouting Squadron Seven, based aboard the heavy cruiser U.S.S. Quincy in Cruiser Division Seven in 1940.

[fltsim.X]
title=Curtiss SOC-1 8-CS-1
sim=SOC-3
model=
panel=
sound=
texture=8C1
kb_checklists=
prop_anim_ratio=-1.76
visual_damage=1
atc_id_color=0000000000
atc_airline=NAVY
atc_type=Seagull
atc-model=SOC
atc_id=8CS1
ui_manufacturer=Curtiss
ui_type=SOC Seagull
ui_variation=SOC-1, 8-CS-1, U.S. Navy
description=The Curtiss Seagull served the Navy well from 1935 to well into WW2. This one was flown by the squadron commander and leader of the 1st or red section of Cruiser Scouting Squadron Eight, based aboard the light cruiser U.S.S. Philadelphia, flagship of Cruiser Division Eight in 1940.

[fltsim.X]
title=Curtiss SOC-1 10-S-1
sim=SOC-3
model=
panel=
sound=
texture=10S1
kb_checklists=
prop_anim_ratio=-1.76
visual_damage=1
atc_id_color=0000000000
atc_airline=NAVY
atc_type=Seagull
atc-model=SOC
atc_id=10S1
ui_manufacturer=Curtiss
ui_type=SOC Seagull
ui_variation=SOC-1, 10-S-1, U.S. Navy
description=The Curtiss Seagull served the Navy well from 1935 to well into WW2. This one was flown by the squadron commander and leader of the 1st or red section of Scouting Squadron Ten, based aboard the cruiser U.S.S. Chicago, flagship of Cruiser Division Five, in 1936.

[fltsim.X]
title=Curtiss SOC-1 CarDiv2
sim=SOC-3
model=
panel=
sound=
texture=CD2
kb_checklists=
prop_anim_ratio=-1.76
visual_damage=1
atc_id_color=0000000000
atc_airline=NAVY
atc_type=Seagull
atc-model=SOC
atc_id=CD2
ui_manufacturer=Curtiss
ui_type=SOC Seagull
ui_variation=SOC-1, CarDiv2, U.S. Navy
description=The Curtiss Seagull served the Navy well from 1935 to well into WW2. This is one was the personal aircraft of the commander of Carrier Division Two in 1939.