I picked up this pack (Code: BIC-ECWG018 - Mortar & 3 crew) at the Alumwell show (WMMS) earlier in the year, it consists of the mortar and three crew but not the barrel. The set is nicely cast and is easy to paint up.
The plastic barrel is from Renedra. The slightly dodgy joint lines which I've tried to cover over with greenstuff. g greenstuff I made the leather bag from greenstuff.
I had assumed the model was based on the only surviving large period mortar, know as Roaring Meg, which is currently on display inside Goodrich Castle. I now think it is based on the cover of Osprey's 'English Civil War Artillery 1642-1651' book and that the illustration was based on the original piece. The figures look very similar to the Oprey book.