Ok James, not to worry your going to make it work. I used to design vac form car bodies and other tools for HPI Racing and other companies.
First, decide if this is a Master Model or a limited use tool.
As a Master you can put detail into it and I can explain this in detail. There are a couple things to consider but totally doable.
As a limited use tool you have to consider your materials right now for higher temps or the tool will deform or bubble and make defects in your parts.
So choose a path and I can explain how you go about making this work.