Been wiring up the rear lights today and it’s not gone great.
The all new Wipac lights re pretty low quality and one tail/stop light won’t even hold the bulb, plus the connector plate inside revolves so the contacts don’t line up.
Those Lucas connectors are really c**p - what’s the go to alternative people are using? Just crimp bullets on, or shall I just solder it all up?

The lucas bullet connectors are not bad, and are easy to replace if you have the correct crimping tool. You can get new bullets to either crimp or solder on, the back female connectors and the crimping tools all fairly cheaply on ebay.

I don’t have the correct crimper but I am good at soldering. I’ll get some replacement bullets and give them a go.
In other news, my can of Maplin contact cleaner has made a hole in my new paint!! Grrr.

You can get new bulb holder and wiring for Defender side and stop/tail lights. When they rust inside they keep blowing bulbs and are so cheap its silly not to renew them. Look on EBAY for them. My rear ones were rusty and blowing bulbs so i did them all and no more blown bulbs now. A previous owner had bodged two of them and used tape and a yellow washing up glove to stop water getting into them too!!!!!!!!

I bought a bunch of new lights just as you describe, the bulbs were either very loose or wouldn't stay in. I bought elsewhere and took them back, but needed a short term fix for an MoT and glued the worst ones in with hot melt glue.

Don't do that.

One was a stop/tail light. And there were traffic lights on the way to the test centre. I mentioned hot melt glue. Yes, the bulb fell out in a pool of glue. Got it through though. Took the cover off and held the bulb in as it cooled again.

So other than the Wipac ones, is there a good alternative for non led replacements?
My originals were all rusted to buggery and had to be swapped out but I want the original look.
Are there any other alternatives?

I did find some but I'm afraid I can't remember where or what brand. I'd suggest an open conversation with a decent supplier. (I'd talk to https://www.shop4autoparts.net/).

I renewed every light on my Def TD5 2001 a month or so ago. I used Bearmach brand for indicators and front side lights and bought the following stop/tail LED ones. I left the indicators all as standard and the relay but with higher output bulbs in them. The front side lights i used LED replacement bulbs which are now a bright white colour.
I also went for new Chrystal Headlights with 100W bulbs in them as the originals looked yellow and as if they were candle powered.
All of the changes were simple to do but i had to use some soldered joints and black ins tape. I found one of my rear lights to be encased in a yellow marigold glove to try and water proof it!!!!!! A nasty bodge and the obvious reason i was blowing bulbs. I too wanted to keep the lights all looking original and not tacky. They are all the original shape and only the stop/tail are actually LED inside as are the fog and reverse lights.

LDX LED Stop/tail were from boltonbits on EBAY £24.99
Flasher/Hazard relay from uklandroverspares on Ebay £9.99
Rear indicators from l-r-parts-ltd on ebay £12.99 for two
Fog and reverse LED were from transglobal-trading on Ebay £39.95
new head light bowls 2 x £15.99 from uklandroverspares on ebay
Chrystal headlights x 2 from Brookwells .co.uk £39.14
Bearmach front indicators and side lights off ebay £18.98

All nice and new looking and original plus the light from each is now brighter too. No more blown bulbs either........

Thanks for all the suggestions.
I bought all new Wipac holders and lenses, but I opted for old style bulbs for originality. Unfortunately, I’ve found them to be of fairly poor quality overall which is a shame.
Still, some standard LR fettling later and they’re all working now. I’ve used some crimp bullets in place of the Lucas connectors in the tub connection point where I couldn’t get a good contact.
I refurbished the original headlamps but I expect I’ll be cursing them as soon as it’s dark.