Value of Antique Engraved Silver Tray?
You can contact online appraisal services like https://appraisily.com/ For a small fee they can appraise your silver platter.
Value of Zenith SL2505?
I would recommend to contact an online appraisal service, see for instance: http://www.appraisily.com/
Large Vintage Storage Trunk Worth
I would recommend you to use this online appraisal service: http:\\appraisily.com Regards
Vintage Items as an Investment
For sure you can invest in Antiques, but if you are not an expert, I would recommend contacting one. For instance, http:\\appraisily.com offers such a service online.