In case this helps anyone else ,I have successfully setup SSL VPN from a chromebook to my DrayTek Vigor 2762 using instructions in the following on-line post by Steve Tomalin in Google's Chromebook Central Help forum:
https://productforums.google.com/forum/#!topic/chromebook-central/QZrhsTu2X1s
Firstly you need access to the Android Play Store on the chromebook so you can install the DrayTek Smart VPN Client for android.
Next in the Chrome browser , you need to open the url: chrome://flags#arc-vpn
When this url is loaded , change the value to "Enabled" and reboot the chromebook a couple of times.
You can now run the DrayTek Smart VPN Client and configure it to connect to your Vigor router( Assuming the router supports SSL-VPN)
Once connected you now have access to the remote LAN resources from chrome apps as well as android apps on the chromebook.
