Doth hast no one shampoo bottles??!!
Really??!! Whiskey Tango Foxtrot?! I'm starting to have a hunch that the game designers (AKA miscreants) have intentionally left the shampoo bottles absent so that we, the player base, get fed up and spend Airport Cash on them to get our Hotels finished. Jerks.
What's Needed:
4x Shampoo Bottles (Hotel)
4x Reinforced Frame (Fuel Station Level 3, req 6)
4x Triple Wire (Fuel Station Level 3, req 6)
5x Transmitter (Fuel Station Level 3, req 6) [this is the orange one, not the Powerful Radio Transmitter used for Malta]
2x Ergonomic Chairs (Level 4 Control Tower, req 2)
2x Ampere Meters (Level 4 Repair Base, req 3) (also needed for Level 4 Control Tower)
1x Lining Plate (Level 4 Repair Base, req 3)
2x Laser Cutters (Level 4 Repair Base, req 3)
3x Hull Parts (Level 4 Repair Base, req 3)
I now have sufficient quantities of Smoke Detectors and Paper Shredders to fulfill the Level 4 Control Tower -- if however you yourself are assorted for them (as in, you've got them to give) but need them yourself, go ahead and send them and I'll send them back. Same goes for Towels (have tons now!), DND Signs and Bracelets (enough to host a small rock concert). If you need 'em, send them and I'll reciprocate.
Hopefully, my sending Power Sources, Ampere Meters and Laser Cutters are satisfactory for those sending me Fuel Drums. (Skyjacker, I'll send you Ampere Meters right off the bat). Anyone else sending Canopy Glass, Paint or Air Conditioners (you know who you are) will (continue to) be ignored.
Send something odd (Air Conditioners are not odd) and I'll visit your city and figure out whatcha need.
If I send you an Ampere Meter or a Laser Cutter, please feel free to "Send In Return"... I need them just as badly. Kinda stupid that you're assorted to send them, but can't send them to yourself.
I also have come to the hypothesis that the longer a plane from your fleet lands and sits idle (before you can unload it), the chances of receiving (useful) items dramatically decreases. These 4:20 flights to Rio with no payoff (in parts, see above) are starting to chafe.