Trek USPS road bike identification

[kingpe11]

Hi, first contribution to this site and asking for advice. I am keen to sell my old Trek USPS road bike. It’s in good condition and complete minus cabling, tyres, bar tape and pedals. Old Ultegra gearing, 9 speed rear cassette. My problem is I’m not 100% sure of the model. I think it’s a 5900 but don’t want to advertise the wrong info. Colour is ‘titanite black/bright silver (again, I think).
I’d add a photo or two but don’t know how to. Any assistance appreciated.

[AUbicycles]

This is how to include a photo:

viewtopic.php?t=23303