Here's hoping you dad-in-law gets to see the Fleet Bipe in the air...!
The PIPE Here again - I've got a similar special place in my own heart, to what you're doing for your own dad-in-law, for remembering my late RC flight instructor Sam Frey (1920s-1996) from Cape Cod, who taught me to fly RC in the late 1970s, through to about 1981-82.
Sammy used to have sooo much FUN with a secondhand Sr. Telemaster that he had, acquired with a patchwork of MonoKote in various colors covering its frame, powered with an Enya 90-FS four stroker engine, flying it in amazing low-altitude maneuvers that could only best be described as an RC aircraft "cavorting", with low-altitude "flip-tail" inside loops, wingovers, and just generall "stooging around" with it, never over about 40-50 feet of altitude, all with the same sort of "knobby" single stick RC radio user interface I had chosen for my own radios, all of which I have built myself, right up to the present day.
Since my current set of "wheels", the 2003 Mercury Gran Marquis four-door car I acquired from my now non-driving mother (whom I still live with!) cannot easily accomodate a Sr. Telemaster of my own to remember Sammy with, I chose to get a Telemaster 40 kit instead late in 2009, for powering with the Fleet's Saito FA-56 mill...sometime later, when I can get back to work and save up the money to get a used 2005-07 Ford Focus station wagon, THEN I'll have the room to transport a Sr. Telemaster that I'd build either from plans, or from the Hobby Lobby kit (when they get a new kit cutter for them!) to REALLY honor Sammy's place in my own life, and I've even got an example of OS's early-1980s equivalent four stroke, the FS-90 rear camshaft engine, to what Sammy was using in his Sr. Telly, to power my own Senior Telemaster someday.
Here's hoping that you can get the Fleet you're building completed for next Spring, so your dad-in-law can get to see it flying...!