The bag arrived today. Here are the measurements that I promised. All units in inches - sorry metric fans, that's what my tape measure reads:
Interior main compartment - 18"W x 5.5"D x 10.75"H. You could probably fit something deeper than 5.5" in there as there is some flex. The bag is definitely bigger than my scope, but I'll save some foam packing material next time I get a box with some and use that to pad the voids. The bag has an internal strap to hold down the scope, but there's a fair amount of space between that and the top of the scope. It has 3 external pockets, one big one and 2 smaller ones on the sides. There's also a flap that divides off a small area in the interior next to where the scope goes, and a mesh container underneath the top that is good place to throw probes.
The bag does have a big TEquipment.net logo embroidered in the front flap, so if that sort of thing bothers you, look elsewhere or toss a sticker over the top of it.
It appears to be really well made, and I think will make a good home for my Rigol.