Limiting # of Componets help

Ok Im at work : )
Just have my data here and came up with an component for enhancing ships, problem is I cant figure out how to limit it to just one per Ship or Base.
Not sure if SEV will except a - for Space. I will not be able to test this until later so If any one has Ideas, Please feel free to comment. If I cant limit them they have the power to be abused

Name := Ship Extension Small
Description := Extension to a starship for equipment.
Picture Number := 9
Maximum Level := 4
Tonnage Space Taken Formula := 0 - ([%Level%] * 25) ------------>Fixed typo now starts as - 25Kt
Tonnage Structure Formula := -30 - (([%Level%] - 1) * 25)
Cost Minerals Formula := 200 + (([%Level%] - 1) * 25)
Cost Organics Formula := 200 + (([%Level%] - 1) * 25)
Cost Radioactives Formula := 200 + (([%Level%] - 1) * 25)
Supply Amount Used Formula := 0
Ordnance Amount Used Formula := 0
Can Be Placed On Vehicle Types := Ship, Base
Can Be Placed In Ship Sections := Inner Hull, Outer Hull
Component Type List := Technological
General Group := Cargo
Custom Group := 0
Number Of Requirements := 2
Requirements Evaluation Availability := AND
Requirements Evaluation Allows Placement := TRUE
Requirements Evaluation Allows Usage := TRUE
Requirement 1 Description := Empire must have at least tech level 1 in Cargo.
Requirement 1 Formula := Get_Empire_Tech_Level("Cargo") >= (1 + ([%Level%] - 1))
Requirement 2 Description := The vehicle size must be at least 200kT.
Requirement 2 Formula := Get_Vehicle_Size_Tonnage() >= 200
Number Of Abilities := 1
Ability 1 Type := Combat To Hit Defense
Ability 1 Description := Extension makes Ship [%Amount1%]% easier to hit in combat.
Ability 1 Scope := Space Object
Ability 1 Range Formula := 0
Ability 1 Amount 1 Formula := -5 - (([%Level%] - 1) * 5) ------------>now starts as a -5 Defense
Ability 1 Amount 2 Formula := -20

and Componet # 2

Name := Robotic Maintenance Pod
Description := Robotic Maintenance helps maintain ship.
Picture Number := 9
Maximum Level := 5
Tonnage Space Taken Formula := 25
Tonnage Structure Formula := 25
Cost Minerals Formula := 200 + (([%Level%] - 1) * 25)
Cost Organics Formula := 200 + (([%Level%] - 1) * 25)
Cost Radioactives Formula := 200 + (([%Level%] - 1) * 25)
Supply Amount Used Formula := 0
Ordnance Amount Used Formula := 0
Can Be Placed On Vehicle Types := Ship, Base
Can Be Placed In Ship Sections := Inner Hull, Outer Hull
Component Type List := Technological
General Group := Miscellaneous
Custom Group := 0
Number Of Requirements := 1
Requirements Evaluation Availability := AND
Requirements Evaluation Allows Placement := TRUE
Requirements Evaluation Allows Usage := TRUE
Requirement 1 Description := Empire must have at least tech level 1 in Cargo.
Requirement 1 Formula := Get_Empire_Tech_Level("Robotics") >= (1 + ([%Level%] - 1))
Number Of Abilities := 1
Ability 1 Type := Ship Maintenance Cost Modifier
Ability 1 Description := Robotic Maintenance decrease maintenance cost by [%Amount1%]%.
Ability 1 Scope := Space Object
Ability 1 Range Formula := 0
Ability 1 Amount 1 Formula := -0 - ([%Level%] * 5)
Ability 1 Amount 2 Formula := 0

Thanks