Thanks, everyone for your advice! With a little help from a few new tools and some VERY helpful youtube videos, I successfully atook the crown out of my Speedmaster and removed the movement. The screw for the top pusher was really loose. Instead of taking the time to fully disassemble and clean the pushers, I chose to just cut my losses and tighten them both. I then swiftly put the watch back together with the understanding that it will need a service at some point in the next few years -- just not yet. I got the crown back in without incident, greased the main gasket, replaced the dust cover and back. Everything winds, sets, and chronographs properly. Victory! Pics or it didn't happen...
Good old YouTube comes up trumps again. I've learned plenty from YT over the years too. Some bizarre stuff that you'd never think of is on there. If it can be fixed, someone's done it, filmed it and uploaded it. Gives you a real sense of satisfaction too when you do something yourself. Must dash, I'm halfway through spaying my dog at the moment and I think she's coming round.........
Well done, but next time make sure to fit the dust cover on the movement before laying it down dial up.
Very brave of you! That's great! I tried fixing something minor in an IWC once and eventually gave up and sent it in.