Since I don't care about checks and have never seen a picture of an L1011 with three stairs anyway, here's the simplest solution. Door 3 has proved elusive and the Walter Becker (half of Steely Dan) song "Door Number Two" keeps running through my head after an overtime day of this. Enjoy L1011 Captains!

Copy the config into notepad and save it as gsx.cfg. If you haven't ever set up your L1011 for GSX, create a folder named " CS_L-1011-1" here: C:\Users\[YOU]\AppData\Roaming\Virtuali\Airplanes\ Drop that sucker in and P3D will automagically find it.

[aircraft]
nosegear = 18.18
refueling = 0
battery = 1
pushbackraise = 1
pushbackdummyevent = 0
pushbackcheckengines = 1
iscargo = 0
trafficcones = 1
preferredexit =  1
wingrootpos = 2.37 -0.76 0.91
wingtippos = 23.77 -9.75 0.91
fuelpos = 9.50 -9.17 0.03
waterpos = 0.00 0.00 0.00
lavatorypos = 0.00 0.00 0.00
gpupos = 1.25 17.49 -2.06
engine1pos = -10.67 0.61 -2.44
engine2pos = 0.00 -12.19 4.88
engine3pos = 10.67 0.61 -2.44
engine4pos = 0.00 0.00 0.00

[exit1]
pos = -2.50 21.77 -0.16 10.50
code = 0
embeddedStair = 0

[exit2]
pos = -3.18 7.20 -0.11 -3.50
code = 0
embeddedStair = 0

[exit3]
remove = 1

[exit4]
remove = 1

[service1]
pos = 2.86 20.68 -0.16 0.00
code = 0
embeddedStair = 0

[service2]
pos = 2.78 -15.13 -0.46 -0.00
code = 0
embeddedStair = 0

[cargo1]
pos = 1.52 12.73 -2.19 0.00
code = 2
name = Exit 2
embeddedStair = 0
uldcode = BELT

[cargo2]
pos = 1.69 -10.20 -2.19 0.00
code = 2
name = Exit 2
embeddedStair = 0
uldcode = BELT

[cargomain]
remove = 1