There are 3 base models for the 6000 series:
 
6460
6420
6410

The DR64x0 MkII has built in Wi-Fi.  Do not use MkI firmware on MkII routers and vice versa.
 
The firmware in these folders will work on all 3 base models, 
just be sure to use the firmware with the correct wireless option. 
i.e. No wireless, Edge or HSDPA.

The firmware will automatically detect if a PSTN or ISDN 
module is installed so this is not important when choosing 
the correct firmware version.
 
The firmware codes are in the format 8xxxxyyy
where xxxx is the firmware revision 
and yyy is the wireless option.
 
WVS = 3G / HSDPA module (Novatel)
WGS = 3G / HSDPA / HSUPA module (Option NV)
W7S = GPRS / Edge module (Siemens)
9VS = No wireless module fitted
 
Each combination results in a different model name being reported by ATI5. 
The following table shows all the Annex A variants:
 
DR6410-00A DSL(A) 
DR6410-0IA DSL(A) / ISDN 
DR6410-0PA DSL(A) / PSTN 
DR6410-E0A DSL(A) / Edge 
DR6410-EIA DSL(A) / Edge / ISDN 
DR6410-EPA DSL(A) / Edge / PSTN 
DR6410-H0A DSL(A) / HSDPA 
DR6410-HIA DSL(A) / HSDPA / ISDN 
DR6410-HPA DSL(A) / HSDPA / PSTN 
DR6420-00A DSL(A) 
DR6420-0IA DSL(A) / ISDN 
DR6420-0PA DSL(A) / PSTN 
DR6420-E0A DSL(A) / Edge 
DR6420-EIA DSL(A) / Edge / ISDN 
DR6420-EPA DSL(A) / Edge / PSTN 
DR6420-H0A DSL(A) / HSDPA 
DR6420-HIA DSL(A) / HSDPA / ISDN 
DR6420-HPA DSL(A) / HSDPA / PSTN 
DR6460-00A DSL(A) 
DR6460-0IA DSL(A) / ISDN 
DR6460-0PA DSL(A) / PSTN 
DR6460-E0A DSL(A) / Edge 
DR6460-EIA DSL(A) / Edge / ISDN 
DR6460-EPA DSL(A) / Edge / PSTN 
DR6460-H0A DSL(A) / HSDPA 
DR6460-HIA DSL(A) / HSDPA / ISDN 
DR6460-HPA DSL(A) / HSDPA / PSTN