With the release 2013.2, script deployments are now exposed for scripting. This article provides a a snippet on how you can perform a scripted saved search on the Script Deployment record using the ID (id: scriptid) to return the deployment's Internal ID.
var filters = new Array();
filters = new nlobjSearchFilter('scriptid', null, 'is', 'customdeploycustomscriptcustomscript_sui'); //this is the value you can see of the deployment's ID field
var columns = new Array();
columns = new nlobjSearchColumn('internalid');
var rec = nlapiSearchRecord('scriptdeployment', null, filters, columns);