@Gordon Wills
please start a new thread if you have new query/issue. In general, if you have valid license you can use whatever version of the software you need (provided you are not exceeding the number of seats). Please check the site were you download software from if 10.3.2 is available (https://symantec.flexnetoperations.com/control/symc/registeranonymouslicensetoken). If not, contact Customer Support (https://support.symantec.com/en_US/contact-us.html).
FYI support for Windows 10 was provided in 10.3.2 MP10 (currently MP12 is the newest release).
@shift88
were you able to get the trial version you were looking for? If yes, please mark the thread as solved