Do you have the japanese Metal Gear Solid 4 Special Edition, which included the game + steelbook in that big slipcase ?
It's this one:
https://www.metalgearinformer.com/?p=5144
I'd be interested in a complete copy of that edition.
Apart from that, wishing you all the best. Always sad to hear when other collectors have to sell their stuff due to some problems. Hopefully better times will come soon!