OK so I did this after the automatic configuration of the printer (not the manual)

lpinfo -l -v gives:

Device: uri = socket
        class = network
        info = AppSocket/HP JetDirect
        make-and-model = Unknown
        device-id = 
Device: uri = beh
        class = network
        info = Backend Error Handler
        make-and-model = Unknown
        device-id = 
Device: uri = canon:/dev/lp0
        class = direct
        info = Gutenprint Parallel Port #1
        make-and-model = CANON
        device-id = 
Device: uri = epson:/dev/lp0
        class = direct
        info = Gutenprint Parallel Port #1
        make-and-model = EPSON
        device-id = 
Device: uri = hpfax
        class = direct
        info = HP Fax (HPLIP)
        make-and-model = Unknown
        device-id = 
Device: uri = hal:///org/freedesktop/Hal/devices/usb_device_ffffffff_ffffffff_noserial_printer_CN33I4116P7E
        class = direct
        info = hp photosmart 7550
        make-and-model = hp photosmart 7550
        device-id = MFG:hp;MDL:photosmart 7550;CLS:PRINTER;SN:CN33I4116P7E;
Device: uri = usb://hp/photosmart%207550?serial=CN33I4116P7E
        class = direct
        info = hp photosmart 7550 USB #1
        make-and-model = hp photosmart 7550
        device-id = MFG:hp;MDL:photosmart 7550;CID:hpdeskjet_5550A851;CMD:MLC,PCL,PML,DW-PCL,DYN,DESKJET;CLS:PRINTER;DES:hp photosmart 7550;SN:CN33I4116P7E;S:0380088084001000003c148005cc2500042c358004f;P:08C0,FL,B0;J:                    ;
Device: uri = hp
        class = direct
        info = HP Printer (HPLIP)
        make-and-model = Unknown
        device-id = 
Device: uri = http
        class = network
        info = Internet Printing Protocol (http)
        make-and-model = Unknown
        device-id = 
Device: uri = ipp
        class = network
        info = Internet Printing Protocol (ipp)
        make-and-model = Unknown
        device-id = 
Device: uri = lpd
        class = network
        info = LPD/LPR Host or Printer
        make-and-model = Unknown
        device-id = 
Device: uri = parallel:/dev/lp0
        class = direct
        info = LPT #1
        make-and-model = Unknown
        device-id = 
Device: uri = cups-pdf:/
        class = file
        info = Print into PDF file
        make-and-model = Generic PDF file generator
        device-id = MFG:Generic;MDL:PDF file generator;DES:Generic PDF file generator;CLS:PRINTER;CMD:POSTSCRIPT;
Device: uri = scsi
        class = direct
        info = SCSI Printer
        make-and-model = Unknown
        device-id = 
Device: uri = smb
        class = network
        info = Windows Printer via SAMBA
        make-and-model = Unknown
        device-id = 
Device: uri = socket://192.168.0.100
        class = network
        info = Xerox Phaser 6350DP;PS5.0.0 192.168.0.100
        make-and-model = Xerox Phaser 6350DP;PS5.0.0
        device-id = 



lsusb gives

Bus 005 Device 002: ID 04b8:011e Seiko Epson Corp. Perfection 1660 Photo
Bus 005 Device 001: ID 0000:0000  
Bus 002 Device 004: ID 03f0:3e02 Hewlett-Packard 
Bus 002 Device 001: ID 0000:0000  
Bus 004 Device 001: ID 0000:0000  
Bus 003 Device 001: ID 0000:0000  
Bus 001 Device 001: ID 0000:0000  

and then

hp-makeuri 002:004  gives:

error: Device not found

as does
hp-makeuri CN33I4116P7E