Thanks everyone for your thoughts. I've almost got it... Great advice on sticking with the instrument data structure David, thank you.
I've converted a symbol to an instrument in Spotlight, but I still can't figure out how to change the default instrument data so that the changes get recalled every time an instrument is placed on the page. ie: Source Four 19 dg is always placed by default with 575W lamp... Say I'd like it to appear default as 750 Watt in every instance, is there a way to make that stick? (I'd prefer not to have to manually change 200 instrunments on a plot).