The Frankie clones are dead simple to do, I used a Mod maker 510 with the 22mm top washer and large positive nut, a piece of copper sheet from ebay and made a small washer out of an ice cream carton to fit on the back of the fire button(it was a cheap project and I didn't want to spend £6 on a new button from mod maker.) I'm still using the original bottle but only because it works, albeit not great, and it came with a pack of 6 spares and I thought it would do for now.
The only tools you'll need are a hacksaw, a 12mm drill bit, a file and a vice or something to help bend the copper sheet. To give you an idea of my skill level, my wife has banned me from all DIY jobs in the house, and this only took half an hour, a competent person could probably do it in 15-20 minutes.