Which one of these jacket twins is a keeper?

I think the right size for you is the 38, considering that the back length is also right.
Of course it all depends on your willpower, as you yourself admitted that the lock down period was not lenient for your weight.
When you lose weight, not only waist decreases, but also chest and partly shoulders.
Of course if you don't want to lose weight and if you want to wear the jacket mainly in winter, with bulky sweaters, keep the size 40!

 

I took another closer look at the pictures and realized that I was fooled by the length of the 40. At first I thought the 40 fits better, but on closer inspection, the 38 is perfect (for my taste). But both are good jackets. I would keep both if financially it fits. one with a layer, the other with a t-shirt.

 

40 looks better.

 

40

 

The 40 looks much better especially zipped...I had a similar issue with an A-2 which I wore for years & eventually accepted, that zippered it fitted like a straitjacket. Sized up one...perfect fit open & shut

 

Much cleaner fit.

 

For me it's obvious the 40 jacket fit overrides any collar perferences

 

38 looks perfect, like a bespoke fit. The 40, by contrast, looks more off-the-rack.
Granted, the 40 fits, sure, and, should you choose to pursue this (crazy difficult) form of body transformation, it will allow you to maximize belly robustness (winter storage!), but for your frame right now, I think the 38 is spot on.

 

Expect for the part where the waist is too tight while zipped up. Can’t you see the bulging pockets?

 

I say keep them both; one for wearing a sweater underneath and one for just a shirt in mild weather. Failing that, I vote for the 40.

 

Definetly 40, never been a fan of tighter fits

 

I would keep the size 40

 

I'm thinking the size 38 will gradually form better around your physique over time especially when it is fully broken in and will be the more flattering of the two. The size 40 will be the more versatile of the two

 

38.........all day

 

I don't mean to be rude, but i don't think either jacket really suits you. From my point of view, your physique is not made for this type of jacket...

Edit: In particular, when both jackets are zipped up, there is something wrong with the proportions between the belly area and the top of the jacket. Somehow both jackets size 38" & 40" look too tight in the belly / hip area.

 

Here is an illustration of what I mean exactly. The change from lower to upper section is kind of weird. Of course, the CR jacket has its own cut. Originally made for and worn by lean motorcycle racers, that could be a reason why in old photos the jackets look different...