750hp,
Dejavu - I helped a friend over a decade ago buy an Arntz from Kassabian for about the same price, same SBC motor (originally a Traco 350 setup), same type title situation and questions too. This might be titled as a SPCNS Year 0000 first titled in 2003, so you may check that with a photocopy of the title to verify it. Many cars were done like this back then before SB100 came out, but they had to pass smog. We went through this with Kassabian as well on my buddies' car just for him to buy it. As I recall, they've had at least a handful of Arntz and PB cars come through there in the past ten+ years that I've seen. Its been an interesting adventure watching my friend getting to know his Arntz and seeing the additions and subtle changes to customize it how he wanted to. He can do custom things with this car as there are no rules since it started as a one-off custom to begin with. His car has become something really fun and different to work on and discuss over the years. A lot more work than going out and buying a painted roller, that's for sure, but then again if you like learning and customizing, this car might be the ticket.
If you are looking for something more accurate to a real Cobra, this is probably not your car -
However, if you want something unique and different with a nice solid (STOUT) chassis, legroom, and some other interesting challenges to work around, its a neat car to start with or even keep once you've made some upgrades. As a buyer, I would try to find out if its a virgin Arntz or see if it is in fact one of the cars that PB set up in the past. After seeing my buddy go through his car and what upgrades were needed, I would not hesitate one bit to buy a solid Arntz car and just go through the drivetrain and suspension a bit, and just drive the pants off the car and have fun. Just ask anyone who has owned or driven one a few times. The first Cobra I drove was an Arntz and one of our members here ended up with it the week after I drove it. Maybe he'll read this post and comment, and he even autocrossed it a few times
They can be a really fun and interesting car if set up right. Of all the small fixes and uprades, the one small snag was putting a good rollbar in it, having to cut away quite a bit of glass and fabbing up some fixtures in tight spaces to adhere it to the the side and frame crossbars. It can be done with patience, but its not a one-day job that's for sure. Something else worth noting, some of these cars can be tad heavy though, super heavy chassis and thick body glass too. Depending on what type/version this Arntz/Butler/PB car this is, I've seen a few weigh in at over 2,860lbs with s SBC; can be a smooth ride though with the right suspension setup. Looking at the photo one can see the nice thick wood rim signature Nardi steering wheel in the car too.
Good luck.