I believe pre war means before WWI, the best being after 1900. Between the wars means between WWI, and WWII, as few if any double rifles were made in the UK between 1940, and the end of WWII in 1945, they were to busy dodgeing bombs, and makeing war weapons, Doubles are still well made into the 50s however, by most of the makers.

The 470NE will draw a premium when you sell, but it will cost you a premium when you buy as well. One thing to think about is, many people find after useing a double rifle for a while, that they are simply not double rifle people, and sell their double, or trade it for a very nice bolt rifle. It is my opinion, that a person new to double rifles, should buy a USED newly made double, for a much lower investment. The monitary apprecieation factor of UK doubles is not what it used to be,when guys were buying UK made doubles from India at pennies on the dollar, and selling them in the USA for ten times what the paid, that boat has sailed. The used double rifle market, today has about peaked, and unless you find a real bargain, you will not make much on the resale, if any. There is some real high priced junk out there for the unschooled to get hooked into, as well.

With a good used , "NEW" double, your investment will be $8k-15K, and the higher end ones like the Heym will hold their value very well, and to a lesser degree so will the Merkel. You can buy a 500NE, or 470NE merkel used in the $9K area, if you shop, and when you sell you will, at least, get your money back, if you decide you are not into doubles that much! Or it can be used as a good down payment on a more expensive double, UK if that floats your boat, if you fall in love with doubles, now with more experience! If it were me, I'd buy a brand new $16K HEYM,500NE or 470NE,or have Searcy build me one of his new CLASSICs, or ROUND ACTIONS, and never look back!

I have UK made doubles, German made doubles,Italian made doubles, and even one Japanese made double, and I find them all to be well made, and well worth the money spent on buying them!

GOOD LUCK in what ever you decide, now that you have several differing opinions, to pick from. When you get down to it, in the field, in front of an elephant, what you need is a RELIABLE DOUBLE, chambered for a good NE rimmed cartridge, that is big enough to do the job. ELEPHANTS don't care who's name in engraved on the rifle you're shooting him with, nor will you, at the moment of truth!

......................GOOD HUNTING!