I must have the only upgraded pump in existance. Mine has a cap that simply screws on to the bottom of the seatpost, no issues with it popping out.
I'm pretty sure the Mu 24 is front crank is similar to the Mu P8. The chainring is removable and I believe it is 110 bcd (double check) some of the older ones (my speed pro) were 130mm standard road. Unfortunately the chainguard is bolted onto the chainring so you will lose that, but like others have said it's fine without it, just exposes the chain a little more.
So where are the pictures?!