You'll probably have better luck finding a Mk2. Just refurbish the Mk1 head and fit that to the "new" engine, use the pulleys and water pump as a set to suit either, et viola.
Would fitting a 16v ELX mk.1 head to a later FIRE 1368 block work? Just about to do it, into my Punto Cab. Thinking of fatter pistons clouting the edge of the head deck, change in CR etc - clearances and volumes generally.
Thanks - just checkin. Tho there's still the Q of what it'll do to the CR - don't know what the 1368 piston crowns are like vs the 1242 - maybe there's more (or less) of the chamber volume in the head vs the piston 'dome'. Maybe it'll create a badly shaped combustion chamber.