For the price of the 7115+gas, perhaps quite a bit less even, You should be ble to find 4 Celestion G12H100 speakers.
Those were on the JCM800 412 bass cab I had as a teen.
Out of those two, I'd probably take the 100€ 7015.
For 280€, the other one should be near mint.
Judging by the model numbers on those links, the drivers were originally Sidewinders, who knows what there may be now
I'd pop the lid to be sure, at least on the more expensive one.
The cheaper is prety much the price for an empty Marshall cab in good condition though.