It all very nice having a merlin piston sitting in your house, but I always think its much better if things can have a use too.
4000 'official' ashtrays were made out of merlin pistons and sold in aid of the RAF (you can read more if you google "merlin piston ashtray"). So I thought that was a good idea, and that's what would become of mine - without the engravings.
It can be used as a coin tray, or as an ash tray. It is perfect for an ashtray as you can hold your cigarette or pipe in the recessed connection points.
Merlin pistons aren't cheap, but you could use any piston you wanted and follow the same process!
Date Made: Feb 2013
Approx Cose: £70
Approx Time: 1-2 hours (depending on your tools)
Step 1: Acquire Piston
You can use any piston you want; buy it new, buy it scrap, or even turn your own!
Step 2: Strip Piston
Depending on your piston, you may need a hydraulic press to remove the connecting 'wrist pin' from between the piston head and the con rod, or it might just be some circlips in a recess.
here is a video that covers both types: http://www.youtube.com/watch?v=B4e7PNzbTzY
I don't have the right tools for the job, so got my local engineers to do it (as well as the following steps), hence why I dont have intermediate step photos.