If it was registered as 3D-AAk it is either too new for me to see, fake or a mistake. The closest you get is:
3D-AAJ:
AIRPLANE ID: PG037 SERIAL NO: 19075 AMRE REGISTRY: N9037U
BAS-EFF: P2581 LINE NO: 97 ORIGINAL REGISTRY: N9037U
ENG-EFF: MODEL-DASH 737-200 CURRENT REGISTRY: 3D-AAJ
MODEL: 737-222 MODEL CONFIG: 200 COUNTRY OF REGISTRY SWAZILAND
MODEL DESCRIPTION: PASSENGER
ENGINE-MFG: PRATT & WHITNEY COMMERCIAL ENGINE BUSINESS ENGINE DESCRIPTION: JT8D
IN SERVICE: YES
