You may find this is more practical,

(the top boost section, don't mind the bottom inverter section). This uses a peak current mode controller,
There are some typos on this exact schematic; the controller should be UC3843 (starts up at 5V supply, not 16), the 20uH inductor needs to be low loss (a "drum" style ferrite choke will do), and some slope compensation would be nice, or a lower value inductor can be used.
To save power, the current is sensed by a current transformer. An off-the-shelf 1:100 CT can be used, in which case the 2.2 ohm resistor value drops a little for the same ratings.
To get more output voltage, the feedback divider ratio changes of course, and the transistor and diode ratings need to increase (use 80 or 100V parts for a 55V output).
Note the SB540 and 1uF capacitor across the transistor: these must be placed as close as possible, so that at the moment the transistor turns off, its load current is transferred to the capacitor, and stray inductances discharge into it. This isn't needed if the SBL2040 diode and output capacitors are equally nearby, but that may be hard to arrange, in which case having the smaller diode and capacitor up close are effective at protecting the transistor.
The 3842 family is easier to use than the TL494, I would say. It's also safer to use -- because of the current mode operation.
Tim