It's a 737-200 with Pratt & Whitney JT3 (or is it -9, I've forgotten!) engines. You are right they are low bypass and noisy, possibly only exceeded by that wonderful means of converting fuel to noise, the BAC 1-11.
Edit: You have made an assumption (probably correct 
) in this part of your text which may NOT be true. I would prefer to let armada come back and offer us more before reinstating it - so it is in the deepfreeze for now.