Having worked my way through many, many old photos and sketches i would say in the civil war few items of personal kit were,'as issued' - if they were issued at all!. Certainly in the first two years. Even when it WAS issued, it appears that many carried what they wanted and how they wanted in the field. Either of those items COULD have been used since many soldiers would have 'found' an item to replace a lost, stolen or misplaced issue item. Aluminium was not used for cooking and eating items so they would have to be that old stand-by - tin plate. I do not think that there were any issued items with a strap loop either, but there were plenty of German famiies donating to their sons' kit with those 'handy items' brought from home. This was not a modern up-to--dte and well-supplied army with plenty of kit in reserve - it was a scratch-built army and there was not much immediately available in the first few years while stores, suppliers and 'official patterns' were sorted out (it took about 30 months to sort out enough rifles for the army!). Yes the Union was up and running by 1864, but the Confederates had all sorts of problems with issue kit from Day 1.
It was a hard struggle getting weapons and uniforms initially and there are stories about issuing by company so that each company looked the same - even if the others didn't. A classic case were the Zouave regiments who gradually adopted the issue uniform because there was no available replacement for their rather unique dress, which resulted in a rather 'mixed dress' appearance in some cases.
This is before the days of the part number and a few metal items may well have had a 'US' stamp, but suspect that was rare. Any budding Quartermasters out there with inside knowledge?