I agree; both with the texting & the circular cowlings facilitating the ease of conversion.
I was able to crawl through Fifi's interior as well as walking around her. I must've burned through about five rolls of 36-exposure b+w film ( this was long before Internet & digital cameras existed). This was decades ago but I think I still have the negatives stored somewhere.
I'm no expert but offhand, I'd say she's pretty much adhered to the original prototype as far as maintaining originality of its interior. Nothing inside that suggested any modern conveniences or upgrades.
Again, this was long before ADS-B & other modern avionics were mandated for aircraft.
Insofar as the B-17, I was able to see 909 ( long before it's tragic accident ), Thunderbird & Sentimental Journey up close & personal. 909 was visiting Reno, Nevada ( where I live) during its tour of the states. Both Thunderbird & Journey were at the EAA AirVenture aviation event in Oshkosh, Wisconsin.
I had a chance to ride in the B-17 but it was too expensive to me, for a 20-minute ride. I think they charge extra to be able to ride in the nose (bombardier's compartment).
Getting back to the topic. I think the XB-38 makes for a wonderful modeling subject. Certainly it would be an eye-catcher in r/c size.