Hey it looks like a genuinely rebarrelled 'H' SMLE. I see plenty with Heavy barrels but they all lack the 'H' stamp on the very front of the butt-stock like this one. I see a big old date stamp or something on the butt-stock which I am guessing is either an FTR or a normal repair, but either it might be when this rifle got this barrel and was changed to a 'H' rifle. Then it looks like someone turned it into a No5 look-alike.