The only potential downside I can see is that it's bound to cost a freaking fortune.
well, greco double neck on japanguitar: £850
add 50% for a new guitar= £1300
double for the gibson headstock= £2600
a grand for Jimmys signature= £3600
£900 for the certificate of authenticity (its a limited run you know!)= £4500
and lets make it a nice round £5000
so not much, Only 6 times the price of a model of comparative specs and quality from a brand with a smaller advertising budget.