right after a bit of digging and feeling like a total tit.. 
It turns out I was missing a . from the Concatenation operator simple mistake so this now seems to work
and this now effects the {instance-name} as intended.
hope it helps someone in the future!
			It turns out I was missing a . from the Concatenation operator simple mistake so this now seems to work
Code Select 
getoid = ".1.3.6.1.4.1.14988.1.1.19.1.1.2.";
instance = $1;
walk = $node.createSNMPTransport()?.getValue(getoid .. instance);
if(walk == NULL) {
walk = $1;
}
return [true, instance, walk];and this now effects the {instance-name} as intended.
hope it helps someone in the future!
 keep up the good work!
 keep up the good work!