I had both my sons done at 10 months old by a company that visits hobbycraft stores in the south west on certain dates. The actual cast takes about 3 mins per hand/foot, very quick. I waited around 6-8 weeks to get mine back but that’s just because I had to collect them when the guy was next visiting that store. I’m sure someone you’ve contacted directly would be much quicker.
I had mine framed and they are beautiful but expensive. Worth it imo!
It’s basically plaster of Paris so no you don’t take it away there and then. Get it done properly as they look amazing. Had my baby’s done at one week old and spray painted. They dry within an hour but best to leave overnight so just depends on your supplier and what you want with regards to how long it’ll take to get the finished product. The actual casting takes about 3 mins