I don't think Henry's really is interested in film photography in general.
Xpresspost like any courier uses a volume process, trucks pick up items, everything goes back to a central location, then it gets sorted then loaded onto trucks for delivery, the next business day, which could very well be the same truck.
Monday through Thursday, it shouldn't take more then 24 hours, as many trucks do deliveries in the early part of the day, and pickups later in the day, an item picked up ~5PM could be delivered as early as ~9AM, roughly 16 hours later. Fridays are the odd day, most items picked up will be delivered Monday, so yeah, 52 hours wouldn't be unreasonable for a Friday pickup. There are direct carriers that will pickup an item, drive it straight there and then deliver it, tends to be more expensive though.