Sleeper 7769 on train 448?

[B&Ofan]

Hi all -

I am on train 448 in sleeper 4820. On this trip we have an extra Boston sleeper numbered 7769. I suspect it is some sort of deadhead (hopefully to return sleeper service on 66/67) Does anyone know why they choose such a strange number or was it just likely a random numbered entered by an employee?

Thanks!

 

[OBS]

random number...