I had the change at 52. I have taken some form of estrogen since then (40 years). Do I need mammogram?

Yes, absolutely. You need and should have a mammogram once a year- especially because of the age and due to your hormonal replacement therapy that can give you some increased risk for development of breast cancer. Dont wait anymore- go to see your gynecologist or pmd- have a proper breast exam and annual screening mammogram.
YES. In general, you should have an annual mammogram and clinical breast exam performed. The presence of menopause and estrogen exposure potentially increase your risk of breast cancer. The older we get the more risk for breast cancer we have. Estrogen exposure and breast cancer risk is debateable as a causal effect, but most studies show a slight or modest correlation with breast cancer.
Debatable. Doing the math, your age would now be 92? There is limited to no data supporting routine mammography in patients as the age moves beyond 75-80 much less past 90. That being said, at 92 you're more likely to live to 100 than someone who is just turning 40. Surely there are reasons to be seeing your physician on an annual basis including a clinical breast exam. Discuss mmgs with him/her.