Lacking oil pressure at start-up / Hard starting

[tamarac]

2005 6.0 Complaint of had starting.
Owner bought truck earlier this spring of 2009, with 105.000 miles on truck. No previous service records. But could tell that turbo had been changed, with a remain turbo. Now has 113.400 miles on truck.
Engine starts after 15-25 seconds of cranking. Even after a 15 second shut down it will take more than 15 second of cranking to start.
Installed mechanical gadge. (Used sending unite port buy engine oil filter) When engine is running, engine oil pressure is in the 65psi range. When engine is shut off, oil pressure drops to zero in 5 seconds.
Changed engine oil and filter. (Genuine ford filter) Was not able to verify type of filters used previously.
Battery’s are fully charged, start is strong.
Fuel condition appears excellent, replaced both fuel filters with ford parts.
Low oil pressure rises after 10-20 seconds of cranking, as soon as low oil pressure rises above 12 PSI, ICP rises and engine starts. Checked oil level in engine oil filter housing after shut down for one hour, or several days it will be 1/3 full or fuller.
We replace the engine low oil pressure pump and front engine housing. Pump rotors and bore area had some scoring. Did not feel that it could create a extensive long start, but reassembled with new pump. Hard start problem still the same. Test drove for 15 miles still hard start persists. Took for a third test drive. Turbo started making noises.
Removes turbo, exhaust wheel never rubbed housing, intake well had rubbed some. Found material in oil feed inlet port to turbo, Appears gritty, not like fine paper particles. ( from aftermarket engine oil filters)
Any ideas? Is there any info on the engine oil pressure routing? Has anyone herd of a cracked engine oil pick-up tube? Where else might there be areas to look for. We have just received the IDS program, but I feel that won’t help us out now. another qustion, any labritorys that could test the particals that i Found at the torbo oil feed port?