washoutt, to answer your questions...
1. Yes I have
2. Yes I would like to talk you out of taking an Archer.
To be a bit more helpful:
Lundy is well worth a flying visit BUT...
as as Neg G says, there is no help of any kind there. If you break your aircraft, you will be on your own and have to make your own arrangements.
One of the difficulties is that there is no-one on the island who flys and can appreciate what you need to know when you ring them to ask about the surface and the wind.
The surface is rough and you need a low landing speed so a day with good wind from the NE or SW is what you are looking for.
The strip is short unless you are used to short farm strips and the grass is long, but not as bad as it was a couple of years ago when they weren't grazing those fields.
The article in Pilot magazine about 5 years ago tells you all you need to know, but better not make it your first farm strip. In other words try some of the wilder farm strips on the mainland first. If you can't cope with somewhere like Oxenhope, don't try Lundy - its much tougher. If you are looking for somewhere in the south, try Halwell in Devon. Thats easier still, but I still wouldn't try it in an Archer. Do the sums, (temp, weight, grass length, wind) and you could be ok in a Cessna 152 though.
If you have any further questions, ask me here. Don't e-mail me as my e-mail is not reliable.