Ray,
I'm not at all familiar with your model Wellcraft but assuming it is somewhat similar to the Aqua Osprey, finding and accessing the pump is indeed very hard. Since you have seen the "pie plate access" thread, it should give you an idea where it's hidden. According to a former employee, these pumps were a one shot deal when installed with little or no thought on replacement. You might try removing one (or both of the batteries) and see if you can reach, wiggle, crawl into the small opening. Again, it's just a guess but based on what other members have found when looking for this same pump.
Good luck.