That's how I have my sites set up, both accessible via HTTPS and HTTP. You should also avoid using JavaScript, the older engines are too outdated. I've built my sites to CSS1 and HTML 3/4 spec which run on IE5 and Classilla really well. With a bit of work it's surprising how nice you can actually get them looking.
I emulate OS 9 on my dev machine and use local tunnel to test local changes on IE5.