Timing cover and dress up???

You don't have to remove or even drop the oil pan to do the job. The timing chain cover will come out without doing that. I haven't ever had any problems with getting parts to fit right no matter where I buy them. Don't know exactly what to tell you there except your thermostat housing must have been a cheap Chinese part or just defective. I don't know of a place that sells new timing covers. If their really bad I look for a good used one. I haven't had one yet that silicone wouldn't seal up but I'm sure I've just been lucky. Maybe put a want ad in our want ad section for what you need.