Updating RNS 510

[S25 GPL]

I bought a VW Scirocco in January and the sat nav needs to be updated. The unit is a RNS 510

VW will do this for me but say it will cost around £ 180.00 to £ 230.00

I have found out the in the secret menu the following :

Model : HW55
Firm Waer : SW 3970
Maps : MAP HDD 7551

I am thinking these are a little out of date. Can anyone help ?