changing the type of SO on a custom SO

We have all of these customized Sales Order forms.  We have a custom Sales Order - Invoice (SOI) and a custom Sales Order - Cash Sale (SOCS) - customized to have the fields we want and exclude the ones we don't, and so forth.

I recently made a new one (for a specific large customer who requires special packing slips and invoice information).  We would want this to be a SOI, but I accidentally started from the custom SOCS.  Now I assume it will generate a Cash Sale upon billing. 

There's no indicator of what kind of Sales Order this is, or any way to toggle what kind it is.  Not having a way to change them is a problem, but I can't believe you don't even indicate which type of Sales Order a given form is, since it's so important. I can only look at the fields available and infer that it's from the SOCS.