Looking for advice

New member/1st time poster so apologies if this is covered elsewhere. I'm a 45 yo male who hired a search company to find my bparents. I was adopted immediately after birth in Ohio, and records from that time (1966) remain sealed, so I'm not positive they've found the right person. Initial attempts at contact have not gotten a response. I sent a letter w/ delivery confirmation (not signature required). I may not have handled initial contact as well as I could have (included family pics and such instead of a generic communication that would protect her info if another family member read the letter). Nevertheless, I can't undo what has been done. My current game plan is to send a letter monthly with generic family info on what my kids have been up to, etc. After 6 months of that I plan to send a registered letter inidcating that if I don't hear from her, I will begin reaching out to potential half-siblings. That was a long set-up for this basic question: How does one introduce themselves to potential half siblings who may not even know their mother gave someone up for adoption? Both half-siblings are also male, and I get the impression that males are a bit less interested in having contact. I welcome stories of either success or failure...I can learn from either one.