Chris J suggested soft dividers and pouches which I could squeeze in to the same box shape. So I was interested in the recent thread suggesting fishing reel cases. Having looked in to it, I bought the 16291 Reel Case by Snowbee. A pair fits the space in my bag; comes with plenty of dividers; snug fit for larger barrel lenses and lenses on Linhof/Ebony boards. The big plus relative to bags & inserts made for lenses (eg Fossoux) is that the flap opens to reveal all the lenses, without having to take one lens out to reveal the one underneath. We'll see how long it lasts but it seems sturdy (if Made in China). The dividers are quite rigid rather than soft and plump, but that suits me because it takes less space. The whole bag is padded and holds things firmly.
This shot shows the bag with two big lenses: the Fujinon 125mm f/8 and the Nikkor 90mm f/4.5.
and same thing closed:
Regards,
Charles