As I recall we didn't have the SCINS (or HINS) fit until quite a while after GW1. A few frames had a Litton IN platform (I was one of those qualified to use it for the post-GW1 flypast of London that was cancelled due to weather). During GW1 there was an in-theatre 'quick fit' of a LORAN procured from the light aircraft GA world (the oscilloscope-based 'make a fish' device was in chocolate teapot territory). I remember wandering onto the flight deck, seeing a novelty item bolted under my radar repeater and a manual the thickness of a telephone directory on the desk with a note sellotaped to the front saying 'Nav - Please Read'.
The only viable conversion to the new unit was driving to the airfield during 'down time', getting the aircraft powered up and learning how to use it. It soon transpired that it was a great piece of kit for finding desert LZs and getting into Kuwait Intl through the oil-fire smoke, but putting in all the information via the single twist control took an age and the Nav had the only read-out. The other snag that manifested itself was that the budget model had been bought and the rate-aiding ran out of steam above about 170 kts. The result was that when it lost lock the aircraft had to be slowed while it had a bit of a think...