Started tear down of the 261 and I'm a bit perplexed on how the PO(s) had the oil lines routed. It looks to me as if the line out to filter has a plug in it. Return side has a small fitting. Anyone got any ideas or have seen this setup before?

http://i1162.photobucket.com/albums/q530/miami54hydramatic/261%20oil%20lines/092.jpg