What is it about Jack-in-the-boxes? My ds announced he wanted one back in September. He's nearly 5 and we thought it was a bit of a baby toy so we didn't mention it as we hoped he'd forget it ... although knowing his persistence, I had misgivings. On Christmas Eve am, he listed his requirements - oh, yes, a JintheB was top of the list. Well, I said feebly, you can't have everything ... He looked angelic and said, 'I only want ...' and listed about two (small) things and a JitheB!! By now I was guilt-stricken. Child scarred for life etc. etc. Spent about an hour on Christmas Eve constructing a Message from Father Christmas, explaining all about how FC had had the parcel containing the JintheB on top of his sack, on top of his sleigh, and as they were flying over Russia, Rudolph had sneezed and the sleigh wobbled and the parcel fell off .... Much searching in the snow had not revealed the parcel, so a 'token' was enclosed to take to a toy shop, where the 'elves' were going to leave him another ...
There was a dodgy moment when he pointed out that Rudolph couldn't talk (my tale gave him a speaking part!) but I robustly reminded him that reindeer couldn't fly either unless they were magic! He has a vivid enough imagination to buy almost any story if he likes it enough.
Anyway, after all this, unless you can find a traditional toy shop near you, (we went to Humla in Hampstead, Flask Walk, nice but vv pricy!) my recommendation is Letterbox.co.uk which has a couple of different sorts. Some you can get named too. Can't recall where else I looked but Tridias is another good mail order place. Possibly Hill Toy Company too, can't remember, but they're quite traditional.