I owned a P38 a few years ago and suffered the same experience. I drove it 25 miles to the nearest Land Rover garage, was very bumpy but caused no damage to the vehicle. I was then hit with a £700 bill for a new compressor!!
All went fine for about another 7 months until I noticed the suspension struggling to reach its limits again, my solution was to get rid of it as I wasn't prepared to part with another £700. I have since heard you can replace the cardboard washer that acts as a seal within the compressor that is the offending weakness within the compressor for very little expense (pennies) or buy a reconditioned unit for around £100. Had this been an option when I owned one I wouldn't have got rid of it. Great vehicle:Cry: