In the boot, brand new from Martin Robey Ltd UK, there are 7 holes approx 8 mm diameter.
Are they meant to be left open for drainage?
When replacing it I do not recall what the solution originally was, but it was fairly rotten and full of filler.
If not what plugs do you use? The plug kit from SNG Barratt Ltd has only plugs that are 10 mm, hard plastic. See picture.
What is the common practise here? Leave open or get correct plugs?
I asked a similar question a few weeks ago about the rear floorboard area behind the seats. I’m going to give an educated guess that when originally designed, in a wet country like the UK, the thought was that water would certainly get into the car. Not only from minor leaks but from loading wet items like bags of groceries, umbrellas, raincoats, etc. Similar to North America in the winter, where it is almost impossible to get into a car without some snow following you in on your shoes. So the holes were truely drain holes and would have been left open. Another maybe more substantial data point is whether there are plugs listed in the Jagaur Spare Parts Catalogue. I have just looked through the most likely sections of my early cataglogue, printed in 1963 and find none. I suspect if you could do a thorough search of the Jag Lovers threads you would find that this has been discussed bofore so hopefully my thinking is consistent.
Fast forward to now. Many of us never drive our cars in the winter. Or in the rain. Or even live where it rains. And we restore our cars and glue down sound deadening material over said holes. In these circumstances, I plan to install generic solid rubber grommets in these various holes. You can buy a assortment from the various industrial supply houses that will do nicely.
All this takes me back to high school, where I got up one Saturday morning and found an inch of stale beer settled in the rear seat floorboards of my 1957 Chevy sedan, courtesy of my beer swilling, slobtastic friends. There was even a tomato slice floating in the middle of the pool! I only wish I had drain holes then.
Thank you for your answer. Have you then left them open all of them?
I plan to install solid rubber grommets in all the holes. They may not come in the SNG kit but they can be had from industrial supply houses, like McMaster or Zoro.
Think I will do the same, but that means fuel tank now can finally get in and get the old bugger’s fuel system completed. Two years since last the time the engine was alive…
Thanks for your expedite answers. I see now many open them up after some previous owners have sealed them off, others leave them open, others plug them. So many variations.
My experience with these cars are also, have as many drain plugs open as possible. They leak for sure.
Especially leave the plugs open in the footwells. And never glue insulation materials on the floor. Take away mats when parked outside and doubtfull weather is due. So water just go through.
My current car, 63 FHC, now from Oklahoma had glued insulation mats on the floor and had then trapped water. A pity since most of car was corrosion free, prior to restoration. Now all good. 
This is not a decision you have to make right now. After you get the car done, see what kind of water instrusion (leaks) you get when washing it with a hose. If you do a good job with the various seals, you may be surprised to find the car is leak free. In which case, you can add the plugs externally, from the bottom of the car. A trick with the solid rubber grommets is to grind off the “shoulder” on one side, allowing easy insertion, like a plug. But a dab of silicone on it to hold it in place.
BTW, when I wash my car, I always get water pooling on the door sill. This is because the doors are very hard to seal at the glass. The door collects water in the bottom. There are two intentional drain “slots” at the bottom of the door, which let the water out. These should be left open.
Good luck.
My November 62 built Sacramento new FHC still has plugs in all of these holes. They are most if not all made of (now yellowed) opaque nylon. In my opinion, while they do appear to be removable drain plugs, given the holes are there, they are as much about preventing road splash/spray getting back up into the interior. I would definitely replace them with something.
