The  Poulan 52 equipped with a straight bar or a bow bar was most common and seemed to be regionalized to the southern logging areas of the pulp wood country. The engine was supplied by Homelite (24X2 engine) which saw tremendous use in generators and pumps.  The 7hp engines were very reliable engines that were an upgrade from the early Homelite 24X1 engines.  I have limited information about the Poulan 44 or 52 and I don't see any huge differences besides the Casted covers, as the motors and transmissions were the same. The 5200 was built from thicker than average castings making them very durable.   It seems like it worked, as many are found and with minimal work are able to be ran again. The saws are great wall hangers in any collection and pretty easy to work on if one wants to get one running. Many were equipped with the long style cutter (7/8" pitch) which can really hog out wood. With the low end torque of the Homelite engine and geared transmission these were locomotives in the wood.