I was gonna say 54 based on your pad stack. But given your inseam, the 54 might be a bit tall in terms of where your saddle height would be (do you know your saddle height??).
So between a 48 and 51, I'd def say 51. I don't even know for sure if you can achieve a 624 pad stack on a 48?

Here is a pic of my -54- with a pad stack set at around 640, so only 1.6cm higher than you. I think you can imagine you would have a really really high stack on a frame 6cm shorter than mine..
Saddle height in pic is around 73cm.

EDIT - just saw you cervelo fit. Your saddle height is only 1cm lower than mine. I'd def say go with a 51 over a 48. And I would consult a Felt dealer first and make sure you shouldn't be on a 54.
Also, I believe the frame stack of your 2017 P5 48cm, is actually almost 2cm higher than the frame stack of a '48' Felt. That is why you likely need the 51 in the Felt, not 48...

Thanks for all the info…

The felt dealer that I am talking to, has a 48 in stock and can order a 51 for +$75…. And said both can be fitted for me based on my fit numbers… just suggested me to upgrade a riser kit and extensions bars from profile design…

I am attaching a compare measurements of all 3 models… felt 48, 51 and my P5 48….

https://drive.google.com/...Zm/view?usp=drivesdk

Given your stack and reach, I'd personally go with a 51, but thats just me.

Just make sure they aren't pushing you towards a size just because they have it in stock...