Paint mega-disaster (long rant)

Have a 65 Signet that I was getting painted. It's a super nice 57k mile Ca car with no rust on the body, it had some rust in the trunk that needed partial replacement (tire well & a 2" x 9" section provided by me). Decided to do a real thorough job so I bought a rotisserie. Completely dissassembled car to bare shell, completely removed all undercoating and cleaned until spotless. Car had no accident damage other than a few small dings in the fenders/ quarters, a banged up rear valence, & some dents in the roof where someone had sat on it (this was my biggest worry). Originally was having a body shop very close by do it but they held it for a year & only managed to get a couple small dents fixed so gave up & tried another shop that advertises about their resto work. The guy looked everything over & said this would be easy & should have it done within the year (this was 5/06). Their rates were high ($65/ hr) but their quality appeared good. Gave them detailed pics & instructions on everything to be done as well as verbally telling them. Wanted the floors, trunk, & underbody painted with basic detail with concentration on outer body quality. They immediately dug in & painted & repaired every dent, prepped & primered every part (fenders, hood, doors, trunk, brackets, etc) & replaced trunk sections. The shell was completely in primer & looked great & looked to me to be almost ready for paint in 3/07. Appeared only some surface rust on floor needed sanded & painted. Only one guy was working on it at that time as collision work allowed but he seemed very quick & at that time the total hourly billing totaled about $9k which I paid. At this point the work completely stopped. Called about many times in 2007 & 2008 but they said they had too much collision work & they could not get to it. Resigned myself to waiting & finally the owner called, said he hired a new resto guy to work on my car. This was around 4/08. Went up to check progress a month or so later & the guy was doing what looked to be some final detailing of the trunk, underbody, & floors prior to paint. Mentioned I wanted some frame connectors. Wanted a very simple setup using 1" x 2" tube & some plate which I provided. Gave detailed instructions of exactly the setup with pics, then went up & showed them on the car exactly what I wanted to avoid all confusion. Figured it should take at most 4 hours, a local racecar fabricator said he would do it for $200 but wanted to get them painted so gave the bodyshop the go-ahead. Asked the owner what the current charges were & he said he didn't know, his accountant handles that stuff. Called a few days later & he said he had a total, $10,700, & to come up & pay. Said that seemed a bit high for work done, he looked at the billing & said yeah, somethings wrong, there were overcharges. Gave him a check & told him to just use the extra for any future work. A week later get a call (2 weeks ago) to come up & check out the connectors. Go up & am shocked to see they completely changed my design, they channeled the 2" section to 1", mounted the tube vertically & drilled a 1" through hole for the emergency brake cable. They also finished all welds to the level you might see on a high dollar street rod. Was kinda speechless & asked the body guy why he didn't do what I asked, he said his setup was more attractive & stronger. This was a Friday & the more I thought about how many hours they may have sunk into it the more fearful I became. Called 1st thing Monday & relayed my concerns to the owner & told him take the connectors off, didn't want them that way. He said come on up, I did & he said he would take care of any hourly problem so I said go ahead & leave as-is. Get a call this monday & owner says horray, some of body is ready for final paint, come on & take some pics & bring checkbook to settle. Go up & car looks great, keeping in mind only the underbody, trunk, floors, & engine compartment are final painted. Go in to settle, he says total not including paint work done this week is an additional $19,000. I nearly crap myself & say that can't be right, he says it is. Ask to take billing home. Examine & they have been continuously charging me for the new guys labor & total was more than 500 hours. The new guy was working unbelievably slow. Then they charged me an extra $5/ hr retroactively for misc materials excluding paint ($4200 for materials). The detailed billing showed over $2600 for the frame connector install alone!! My grand total is now over $40,000!! Call the owner to discuss & he says it should be another $20k or so to complete the painting. This is with me doing 100% of all assembly work. Tell him to halt all work immediately. Now I have a huge dilemma as to what to do. My 1st plan is to ask owner to settle on a much smaller amount (unlikely) with the 2nd plan bringing a lawsuit. Any which way I'm screwed as he has my car. Suggestions / comments / sympathy please.