Thx for all the the awesome help, very much appreciated! 

Update:

We got on Train and I found a male and female Conductor. I pleaded my case and the male Conductor said you need to get off the Train in Nimes. He then lightened up and said if you like you can buy another reservation right now for Nimes to Gare du Lyon. 
 

I told them I already paid for two reservations (more than enough to cover this trip). I said after Nimes we are willing to sit in the bar car or benches they have between cars. I also said I couldn’t cancel my reservations because the reservations were in French and I didn’t know how to. 
 

The lady Conductor chimed in and said no problem sir and told me if the Train fills up we would have to sit on a bench or bar car. No more money spent.

We met a lady that was desperately trying to find a reservation for the entire train ride Barcelona to Gare du Lyon. None were available. She found a seat near us and is waiting to purchase a reservation. They are some open seats. The Conductors haven’t been around yet, I tracked them down for my issue. Thx again for all the great advice. 

Sounds like things have worked out then! Thanks for the update.

All good thanks again!

Hypothetical question here Ralderton or anyone.

The young lady we met that was on the train that couldn’t get a reservation because the train was full got very lucky, ironically the only empty seat in the train car was beside us. She paid for a reservation while on the train. She had a Eurail pass.

My question is what if a few hundred people did what she did and jumped on the train but didn’t have reservations because they were sold out. What would they do with all these people with no seat reservations? Just curious! It was at least 4 hours into a 6.5 hour  journey before the Conductors came around. 
 

   Cheers, Brian

Highly depends on the situation I'd say. They tend to be harsh for "safety reasons" on high-speed lines. Overcrowding is rarely an issue in Germany though, also a country with high-speed lines...

Experience last year on a cross-border train to Spain : someone next to me didn't have a reservation and had to stand after Valence TGV. It was fine for him, he used a seat in the hallway no problem. After 30 min-1h the conductors came and asked for his ticket. He only had the pass and no reservation so they gave him a 75€ fine + 35€ reservation even though he had found a seat and didn't bother anyone. 

They only checked him and never wanted to check my ticket ! I didn't find the situation very fair... Actually I did hometown in Switzerland - Geneva - Lyon - Barcelona without being checked a single time.

Wow, I thought you could (without penalty) buy your reservations on the train but that being said I was always puzzled for the reason of to many people on the train wanting to buy reservations. That lady with us got lucky, they just made her pay a reservation fee.  Thx for the reply. 

Maybe they didn't check you as you sat on your reserved seat? In the Swedish high speed trains with mandatory reservations the tickets are normally not checked if you sit on your reserved seat. The ticket inspectors only check people sitting on seats where no-one is supposed to sit.

Probably yeah but that doesn't seem exactly fair, they couldn't know I was on my seat. I could've taken the seat of a no-show. Either you check nobody or everybody...

Generally if you let staff know on the platform before boarding they'll sell you the reservation without a fine. They may add a 10€/CHF fee like they sometimes do in Switzerland.

Of course some are stricter than others. As you said you were all lucky.

So buying a reservation on the train you should  get fined, that makes sense for overload reasons.
 

So if a train is sold out of reservations (online)  they might not sell you a reservation on the platform? Thx for the info!
 

   Cheers, Brian