The aircraft model is painted in new PIA livery but seems to be missing 'Pakistan International' titles below 'PIA' logo on fuselage.
The rear section, behind green & mustard colour band, should be in off-white (cream/sand) colour.
The painter has painted entire engines in white colour. Only engine cowling (fan cover) should have been in off-white colour with bare metal engine intake lip. The portion behind engine cowling should have been in bare metal colour and exhaust cone should have been in black colour.

It's a model of a Boeing 747-200B with Pratt & Whitney (P&W) JT9D engines and technically it should have been left in 1980s green & gold or 1990s sporty livery as P&W powered Boeing 747s in PIA fleet did not receive liveries that were introduced after 1990s sporty livery.
Abbas