That's what I've always suspected for the older maps that came with the first Il-2 and Forgotten Battles.
Maybe this explains the relief height inaccuracies that can be seen on some of these maps. For example parts of the Balaton map seem to be too flat, especially the Bakony region north of lake Balaton.

Load up your game, go into the quick mission builder, select Hawk 75A-3 or A-4... await pleasant surprise.

Thinking about doing a new map? I've been looking into the details myself...

What about mohawk?

My own map building attempts were very disappointing. I once had created a map of the northern Kuriles, but when I first opened it in FMB the scale was completely wrong. The islands were much too small and the hills too high. I was unable to fix the problem and that was the end of my career as a map builder.

China.

Nuff said.

But SRTM data isn't perfect either, since it represents the way the world looked ca. 1990-2000 or even later. After WW2, there was a lot of growth and development in the USSR, China and Europe, and even in the Pacific, so you always have to go back to WW2-era maps to make sure that you've got your towns and cities the right size and to be sure that things like reservoirs and coastlines were actually there in the 1940s.

As an example, I believe that the CoD team wasted a lot of effort creating the "footprints" for British towns and cities based on current data, forgetting the fact that the landscape of the UK is incredibly different from the way it looked 75 years ago.

As another example, volcanic eruptions have made some major changes to the coastline of Hawaii and Rabaul since WW2.

I suspect that might be too difficult for my first go around. A lot of roads and towns and such... I'm thinking of Leyte perhaps. A lot of ocean and only some roads and towns in one area.

Which part? There's a heck of a lot of China to model!

It's also a bit trickier to get right because in addition to the massive development which has taken place in China over the last 30 years, during WW2 the Chinese breached levees along the rivers as they retreated, leading to a lot of flooding that isn't shown on immediate post-war maps.

Related to that, parts of China have wet and dry seasons, so maps of riperine areas during the wet season would look very different from the same map during the dry season. (Technically, this is true for other maps as well, for example, a map of Russia during the spring thaw should have the rivers at a higher level, with flooding along bottomlands.)

Next, the landscape of China can be very diverse, and IL2 maps are quite limited in the number of textures they can use.

And, finally, there aren't a whole lot of good, Oriental/Chinese objects or buildings in the game, so any would-be China map-maker would also need to research and create things like walled 1930s era Chinese villages, Chinese temples and pagodas (different from Japanese), Chinese city objects, etc.

My ignorant guess is that places like Hong Kong and Formosa would be easiest to model in terms of getting the water features right, but you'd have to do a lot of editing of SRTM data as compared to WW2 era maps to scale the urban area down and to get the coastlines back to their 1930s configuration.

I'm sure it's on the list somewhere.. just needs the British specific bits.