[la grange]

Hi Laurent,
welcome to the real world.
My advice to you.
First check for phase and allign on what will surely end up being the snare as a common ground. If the recording engineer did is job right, Both Oh should be lined up so it's a mater and placing them both on the snare track time.
You mentioned the room being so so. I would definetely do that and then create an artificial space using the reverb that you think suits the pieces best.
Automation volume will surely be requeired to tame the crashes.
I think that with kind of recording you have to use the OH as the overall drum sound. Leave the snare and Kick track for later. Work on those 2 tracks alone until you have a good sound, the snare and toms will be your guide line. Compression for sure and EQ to fit.
I would start with the 5500, then your 2500 and final touch ups with SSL Eq in that particular order but this is not the only way. Do experiment, you might find something else that works best.
Your Briscati should really be a weapon of choice
Then, fetch the snare and the kick and add them to your OH.
If you do replace the snare sound, be sure to choose a sample that goes along with the snare sound you get from your OH.
Hopes this help.
Have fun, you ll be enjoyig the dynamic of a good drum track far more than samples...

Oli