Insurance for international guitar shipment, ideas?

Any votes for how's best to insure a (G&L) guitar for air shipment from, in tis case, the Pacific Northwest to England?
I hear (fairly obviously) that the shipper's pet insurers are not the answer.
And I feel pretty sure that Fedex, UPS and USPS must all be equally likely to stack a mouse and an elephant the wrong way around occasionally.
My seller just says he ships with the shipper's insurance, and has no problems; when that scheme does eventually have a problem, I really don't want it to be mine and end up holding some prettily-polyurethaned firewood.
This is not a heartbreak GAS romance (at 62??), but it is a purchase I don't want to mess up if I can help it; it fits a major, awkward need of mine really well.

Many thanks for any advice anyone would kindly offer. I just play and record this stuff, I'm unskilled at the world-wise business end!

Best whatever insurance available through the shipper plus drop ship them a flight case and use its shipping box for the guitar in advance. I would not ship a flight case through UPS or FedEx without it being inside its own box. They can get snagged on things and may end up looking like they dropped it from the plane. When selecting a flight case make sure it is for shipping. A lot of the flight cases are designed to be transported by a relatively selective road crew rather than treated as just another heavy package by a shipping company where they are pushed, stacked, banged and buried against the other freight.

The result, your guitar shipped inside the flight case with both inside the shipping box of the flight case and fully insured.

As for the guitar's case, have it shipped separately in the box the guitar store would have shipped everything in. Is this from a guitar store? If not find a guitar shipping box and make sure it is well padded for the empty case.

This is going to be expensive but the guitar will have an increased chance at surviving the trip.

Best whatever insurance available through the shipper plus drop ship them a flight case and use its shipping box for the guitar in advance.

+1. Though if they lose it you'll be out even more money. I can't even begin to imagine the headaches involved in arranging an intercontinental insurance payout

Thanks to you both for your help with this.
I can take some sensible decisions now, and feel much better about it (even if it is looking more expensive..)