AH, I see the problem, you live in the UK and I live in the US therefore my information was incorrect for you.

First of all, Your radio is 35mghz (Uk standard for aircraft is 35, US is 72), the GWS receiver you have wont work with your radio as it is made for 72mghz radios. You will need a receiver that is made for 35mghz operation.

The servo placement for a 4 channel and the first 4 slots on a 6 channel receiver is the same, the 5th and 6th channels are for retracts and flaps. BUT, if your radio is a mode 1 (throttle is on the right stick) the servo placement will be different from what I said earlier as here in the US most everyone (including me) uses mode 2 radios (throttle on left stick) and thats what the placement setup I posted is for.

The F next to the 2 c's on your receiver stands for FCC (federal comunications commision) they regulate the radio waves and whatnot in the US (maybe in other parts of the world as well, I dont know for shure)

Yes, a GWS TX will work fine with your recevier (as long as the shift is the same, mghz is the same, and channel is the same), but I dont know about using 72mghz equipment in the UK, it migth not work right over their as like Is aid before the Uk standard for rc aircraft is 35mghz and US is 72mghz.

Im not shure what Negative shift and postive shift actualy mean (other than - is hitec/futaba and + is JR, airtronics and sanwa), but for your Tx and Rx to operate together they must be on the same shift.

Right now I'm gonna say teh best thing to do is try to return the receiver and eitehr get your money back or get one that works with your equipment. Just tell them you didnt know the receiver wouldnt work with your stuff nad ask if they can either give you your money back or switch it for one that will work.