Regional baggage allowance Stobart Air
 

We have a connecting flight from EDI to DUB on Stobart Air, which is a regional Aer Lingus flight.
I am confused about the baggage rules. We are allowed 2 checked bags on every flight for this trip but this one. I know it's a smaller plane, not a jet so I figured that was why. I did think that you got the same baggage allowance on all legs throughout the same itinerary.

I do not understand the carry on policy. Is is one bag? One bag and a handbag? My husband has a backpack that he bought for this trip and it looks like it is an inch or so too big on all measurements. Is this going to be a problem. We were thinking he could check this if it was too big, but since we have a limit on checked bags that is going to be a problem.
Our trip is 2 weeks long and this dumb 40 minute flight is screwing all our planning up!
Any one have any suggestions or history with the type of flight? It's an Airbus A320.

Are you sure it's not an ATR72? If it is an A320, you won't have any problems as it's the same aircraft Aer Lingus operate across Europe.

You are correct, sorry, I looked at the next flight on our list. It is an ATR72.

ATLLHR, that doesn't sound quite right, is this all booked on one ticket? What is your itinerary?
The EI website does say;
"If connecting from our Aer Lingus service to our Aer Lingus Regional service that the 7KG cabin baggage allowance will apply for both parts of the journey."

Sadly on those tickets including a Regional route you are only allowed the lower cabin allowance. The international segment does not make any difference. Quite a few get caught out by it and it is indeed a pain.

I've travelled on the regional flights regularly over the last 3/4 years, normally with a "mainline" outward leg. Never once have I had my luggage checked for size and I always travel with a full normal sized 10kg hand luggage with no issue. I think you'll be fine.