I've compared the code in ChunkProviderGenerate.java from Beta 1.7.3 to the code in azd.class from 14w18b.
The following terrain settings had the exact same values in both Beta 1.7.3 and 14w18b:
seaLevel was 64 in Beta 1.7.3 instead of 63.
biomeDepthWeight, and biomeScaleWeight both need to be set to 0.0, in order to get full height variation across all biomes back.
The two settings I couldn't find the value for in Beta 1.7.3 were biomeDepthOffset, and biomeScaleOffset.
I checked the code for ChunkProviderGenerate.java in Minecraft 1.6, and those two settings affect minHeight and maxHeight.
If you've already set biomeDepthWeight and biomeScaleWeight to 0.0, then they seem to affect the height universally across all biomes.
The Beta 1.7.3 code seemed to use a lot of math to determine the minimum and maximum height, and I couldn't quite figure out what numbers I should input there.
So, I've played around with both biomeDepthOffset and biomeScaleOffset, until I got things looking as close to Beta as I could.
If you want to play around with it some more, biomeDepthOffset is minHeight, and biomeScaleOffset is maxHeight.
I've set biomeSize to 2, as I felt that setting was closest to Beta's small biomes.
Hey Jeffrey! I found this a couple days ago and was astonished. I had no clue this was possible. Ever since beta 1.8 came out it just has not felt the same. I decided to make a video about it on my YouTube page:
Thanks for this preset...it has really brought me back to Minecraft!