Will there be a difference if I add 75CC - 100CC? (Photo)

Thank you for the question and pictures.  Yes, adding the volume you mentioned will certainly make a different but  will question: will it be the difference that will achieve your desired outcome.  Sometimes adjustments of the surrounding breast implant capsules are also necessary to achieve the desired outcome.You will find that online consultants will not be able to provide you with specific advice in regards to selection of specific breast implant size/profile. Ultimately, careful communication of your goals will be critical.
Generally speaking, the best online advice I can give to ladies who are considering revisionary (upsizing) breast augmentation surgery (regarding breast implant size/profile selection) is:
1. Concentrate on choosing your plastic surgeon carefully.  Concentrate on appropriate training, certification, and the ability of the plastic surgeon to achieve the results you are looking for. Ask to see lots of examples of his/her work.
2. Have a full discussion and communication regarding your desired goals  with your plastic surgeon. This communication will be critical in determining  breast implant size/type/profile will most likely help achieve your goals. 
In my practice, the use of photographs of “goal” pictures (and breasts that are too big or too small) is very helpful. I have found that the use of words such as  “natural” or "D or DD cup” or "more full and plump look" etc means different things to different people and therefore prove unhelpful.
 Also, as you know, cup size varies depending on   who makes the bra; therefore, discussing desired cup  size may also be inaccurate.   
3.  Once you feel you have communicated your goals clearly,  allow your plastic surgeon to use his/her years of experience/judgment to choose the breast implant size/profile that will best meet your goals.  Again, in my practice, this decision is usually made during surgery ( after the use of temporary intraoperative sizers).  Viewing the patient's chest wall in the upright and supine positions, with temporary sizes in place, help select  the best breast implant size/profile for the specific patient.
I hope this helps. Best wishes.

Its difficult to accurately guess the effect of any implant size increase without an examination that lest me feel the skin and the contour of the current implant.  However, generally, to notice a substantial increase form 350 cc, I would recommend at least 75-100 cc.  Otherwise there is a strong chance that the difference is not enough to obtain a satisfactory result.  If the skin is loose, a larger implant will be required.