Not really sure whether the WW2 Panther would be a TL5 or 6 design based on the Tech Level projection chart in TNE. Here is my take on this vehicle as a TL5 version. A TL6 version would have simple stabilisation on the main gun but would otherwise be quite similar.

I have always considered WWII being mainly TL 5 with early appearing TL 6 stuff around 1944.

Actually in FF&S1 Radar is available at TL5 and the design sequences do allow for all types of gun actions so SMGs etc can be designed. So it appears its the tech descriptions in TNE that may be off. I found the problem was actually the TL4 to 5 one, especially for tracked vehicles. According to FF&S1 tracks do not appear until TL5 - TL4 circa 1900, TL5 circe 1930. Which would make things like the WW1 Renault FT17 from 1916 or the British Mk1 from the same period a little difficult to build.

Incidently TL9 is shown as circa 2010, where is my fusion powered starship?

It will be interesting to compare, if I try one with standard FF&S and you do it using the separate hull and turret mod.

Problem is, Leopard when introduced was not significantly better armoured than Panther.  Leopard was a fast, well-armed tank which sacrificed protection.  It would not have stood up well against the opposition guns of the day (100mm on T55).  From the 1970s much better protection was added to the Leopard turret, and tactics of fighting hull-down would have given it a better survival chance.

I think British tanks fit a lot better with FF&S design biases, because they tend to be heavy, slow and unreliable!  Maybe I'll try a Centurion...

These two versions of the same design are quite good. There is a problem with TLs linked to certain dates/years, however it is much easier to vision what a 1940 TL is versus 1950.

One thing I would have liked to see is more steps in internal combustion engines. The best available is at TL5, which is way too low for me.

And I think I'll with future designs construct the turret differently from the chassis as this gives better room for control when designing the same vehicle with a different turret due to different weaponry in the turret. Thus it is easier to keep the chassis with the same design parameters. It will also be easier to assign different armor values and sloping to the turret seperate from the chassis. Overall a win-win situation.

And I do agree that crew stations inside a vehicle is basically too large. A while back I tried to designa WWII jeep, but was foiled by the seating rules. Even cramped seats seems way too large. I am unsure that an open Jeep like the willys really needs seats by the standard rules. The vehicle is bassically a box with wheels and a motor where the riders sits on top.