Congratulations. That is just about the worst argument I've seen on the subject. That has been national policy since before Reagan, and the point is to have that registration data on file just in case of the unlikely event that something happens that requires a draft.
So presumably you are some kind of expert in the currency and accuracy of address information for young men, and yet you are apparently unaware of more accurate and current databases of the names, ages, and yes, even locations and mailing addresses of young men.
Lets just assume the hypothetical that for some reason the government suddenly needs a bunch of people to defend us. Of course, unlike wars 75 years ago the people you need actually need to be pretty skilled. Which is why the current military policy is to reject many applications with limited education. And why a database with little or no educational information is pretty useless.
So your strategy is to rely on a single paper form filed when people turned 18, when in reality the need may well be for educated 24 year old men and women.
Why don't you think about how you would actually find and communicate with young people in an emergency. I'd rather combine the existing social security database, and drivers license databases with data from Facebook and other similar sources than try to rely on the Selective Service database.
Oh, and did it ever enter your thoughts that maybe an equal protection lawsuit related to drafting only men would result in a court order to draft equally from both sexes? In that case I am sure you are convinced the Selective Service registration database would work just fine.
Of course in a real emergency, the entire concept of the Selective Service system depends on the mail to be working, and people not to be moving around. Needless to say in many emergency situations neither assumption is valid.