In the front right of the Tiger 1's hull sat the radio operator who also manned the hull machine-gun, an MG34. Apparently the barrel of this weapon could become overheated and distorted through extended use, necessitating a replacement.
The items shown above are, I believe, standard metal containers for spare MG34 barrels. The larger one can hold two barrels. One of these large containers was carried in the Tiger 1 as standard equipment, beside the radio operator's position.
The photos above show the lid of the case and the internal bracing that held the barrels away from damage.
The case was clipped to the right-hand hull wall, low down, immediately beside the radio operator's seat. You can see photos of the two clips that held it, on this page: http://tiger1.info/saumur/english/radio.html
The item appears to be painted in Feldgrau, if this is indeed its original paint. The two dimples at the bottom of the case are slightly off-center. Considering what is inside, I believe this is due only to sloppy manufacture.
I have not completed drawings of this item yet, but the sketch above shows some basic dimensions.
[1] Survey of a surviving MG case by 'Bergflak'