Alternatively, you could swap out the entire front sight block for a 74 block. Could be a little easier than making a bayonet lug from scratch, assuming the barrel diameter is close.
One last important part of the conversion is to open up the magwell, since Galil mags are a bit wider. But all the work is worth it. That gun looks so much better with the correct mags.
Apex has them for $20. But the rivet pattern is pretty much the same as an AKM, so you could use any mag release tower or trigger guard you want.
https://www.apexgunparts.com/imi-galil-front-handguard-retainer-multiple-finish-options-6180.html