I just spent an hour in the basement with some hG and knockoff freewheel components.

this is what I discovered,
the knockoff is a "falcon" china

the falcon cogs are 2mm, the spacers are 3mm
the shimano cogs are 1.8 and the spacers are 3.2.

the falcon cogs will fit the shimano body
the big shimano cogs will NOT fit falcon body.-without some help

It would be an atvantage to build the falcon body with shimano cogs , this would require a bit of filing.

the falcon body is narrower then the shimano one, the lock nut threads go in deeper.

I stacked the falcon spacers and the shimano cogs and came up with a very nice package,

allstop

the body is too wide to fit in the 120 spacing-back to square 2,
left to right
......everest 5........... pro compe-u6............. falcon7.............. shimano hg7


i guess filing and modifying the u6 is the next step