Will a bull bar from a Defender 90/110 fit a Discovery 1, without modification?

Probably not. A discos bumper has horizontal mounting holes whereas a defenders are vertical

Depends on the bullbar .. a cheap one with 'universal fitting' might, or one that needs welding to the bumper .. but a D1 bumper isn't really strong enough for a bb that isn't properly mounted to the chassis ... they bend when they hit Nissan .. er .. dunno, but small thing, got under the wheels ..

That's a shame, he only wanted £45 for it.

What about Classic Range Rover ones, I'm sure I saw a camel trophy style one that said Classic Range Rover or Discovery 1, but can't find it now. What about the wrap around ones?

I'm struggling to fine one cheap enough to fit a D1 on eBay that isn't too far down south, so just pondering alternatives.

Depends what you want it for really. If it's for posing and looks, then you can easily make anything fit. If it's for laning or off-roading where you might want to push a bush or stone aside then you need a proper chassis fitting one, but many of them decrease ground clearance quite a lot so you lose out 99% of the time, so be careful how it fits to the chassis!

Classic RR is essentially identical, chassis wise wrt bumper fittings etc, as a D1 ..

If you have a bit =>5mm thickness of steel and can make plates up and weld and drill them reasonably accurately then a Defender one could easily be made to fit, just needs thinking about and time to fettle it.

Some of the ready made ones use plates that come from the bumper mounting holes, down, under the bumper and then up again with the round bits welded on (if you're lucky) somewhere below the bumper, hence the ground clearance issues ... chocolate fireguards spring to mind ...

Only my opinion, I wouldn't have one in UK.

I want one to protect headlights and indicators from hedges and the odd deer. Somewhere to bolt spot lights to and give the occasional idiot a nudge will be a bonus