PI Technology Deepscan 400 modification

[nad]

I have a PI Technology Deep scan 400....First time out , found $700 in rings in a swimming hole.in less than an hour..Tonight ,I was sitting with another old geezer and the PI came up when we were discussing Indian copper artifacts.. I had hoped to convert the coil to a wide coil,mount it on a wheeled device and walk for meteorites and copper..When I mentioned the English used this type of pushed coil to find artifacts, he really took off... His searching nets, five or six copper toys a year. plus some other nice items..If this detector can be converted, the targets would be app 4 inches square ,or larger. Depth a foot or less.The coil could be pushed app 1 inch off the ground, or pulled on the ground.One afternoon would equal virtually his whole searching season.(You don't move that fast in your 80's) First question, can this machine be modified for the task. #2, will the larger coil mean less battery life.?... #3, does the target size fit what a wide coil can detect.? There may be an interesting demand created..., What machine would be the best to buy and modify for this type of hunting? A 70's type of machine is a bit behind the curve.....Thank you for your time, cordially Nad