RE: 52" Mr. Mulligan
Your right, it's a World Engines kit.
It is shown, built, on the cover of April 1977 Model Airplane News as a soon to be released kit.
It sold for $47.95 in late 1977.
It has a 52" wing span, calls for a 30-40 engine and the plans show it can be built either 3 or 4 channel.
I have one, unbuilt, in the box that I bought on RCO 5 years ago for $75+$7 shipping.
They are very hard to find now and I saw one go for $110 on ebay about 3 years ago.
I doubt I will ever build mine as I have too many other projects so if anyone is interested I will let it go for what I paid.