Help w/Information & ID for 18th c. Mexican(?) Colonial Serving Tray

hi everyone. i found this piece earlier this week in a thrift store. i was immediately attracted to it because i've never seen a kitchen related plate or tray that looks like it before. i've identified it as an 18 century Mexican Colonial silver serving tray. there are pictures of other examples up online and it really is the only thing that's entirely similar. i would love to conclusively identify this piece. also, i'm hoping someone on this board knows more about these things than what information i've been able to find online so far. this piece is somewhat larger than the other examples i've found. it measures 16 inches in diameter from outer edge to outer edge and 2.5 inches in height. it weighs 2 lbs and a little over 14 oz. also it is more plain in its ornamentation than other examples. i'm wondering if that would possibly help to date it? there are no hallmarks that i can find, but there are squiggly scratches on the underside that resemble the types of scratches that would have been made for purposes of tax assessment back in the 18th century(at least based on my research). The only punched mark i have found is in the dead center of the top bowl area. it is a small round dot. all of the other examples i've found online have this same punched dot in the center. also, this piece was tested for silver content using one of those lazer guns. it tested 85% on the top and 81% on the base. finally, there are 3 areas where it appears that this tray was repaired. i didn't notice this until i got home, but you can see globular metal solder along the interior bottom edge of the bowl portion and corresponding irregularities in the edges along the outside. i'm wondering if this might help to date it? any help will be greatly appreciated...thanks