You'll need to do a few things with this gallery:
1) sort through and include only those objects that date to the colonial/bottle period, and rename this section to reflect that.
2) Add another browse preview block displaying objects from other periods (up to you whether to include before/after battle period in same list, and sort these using Item Sets).
3) Go through each item and, on the "mapping" tab, try your best to place a point at the location of the relevant unit or part of the park it came from (note you won't be able to see the units on the editor, so you'll have to toggle back and forth). After each item is updated, the results will reflect on this map.
4) Play around with the span on the "grid" formatting to get the list to display across the whole screen. You may have to move the map up too.