Bob Saw this when you first posted it and figured someone would beat me to it but since no on has,here's the scoop on the shifter.I've made a few and am going to make a few more soon.
Fitting the knob is not the only issue,you need the whole top half of the 240 shifter because it's hollow and can have the wires run through it for the switch.So what your doing is mating the top of the 240 shifter to the bottom of the 140 shifter.please note there is a plastic ring missing from the 140 shifter in the pix,it would go below the large nut that holds the shifter in on the 140 shifter.First picture shows both shifters before disassembly.

The second picture shows the 140 shifter disassembled.The rubber bushings are shot but you'll toss those anyway.Ditch the snap ring that held the 2 shifter halves together also.

The third picture shows the 240 shifter disassembled.You'll toss everything in the top half of that picture,(reverse lock out and all)there is a special rubber grommet in the bottom of the upper part of the 240 shifetr that can't be seen in the picture (it's inside the shifter and the grommet has holes for the roll pin to go through.

Picture 4 shows all the parts your keeping from both shifters.The early shifter halves are held together with a snap ring (previously mentioned) the 240 shifter is held together with the roll pin.Slide the top half of the 240 shifter over the bottom half of the 140 shifter.mark for your roll pin.Disassemble and drill a hole in the 140 lower shifter half and install your roll pin.It should be noted that you feed the overdrive wires through with the shifter disassembled and slide it together with the wires strung through it.There is also an upper grommet in the 240 shifter,look up in the top shifter half to ensure it's in place or you could be assembling a few times.There is a notch in the upper grommet for the wires to go past it.

The 5th picture shows the finished product minus the hole for the roll pin.

Hope that all makes sense,same thing goes for late 1800's (E and ES) and 164's any questions?!
Bub