The last two pills in my father's 'unknown' bottle are:
Yellow caplet with 577 on the front and 750 on the back
Small beige circle with M2
Thanks again
My brother and I really appreciate the help.
Your M2 maybe?
FUROSEMIDE (Lasix®) is a diuretic. Diuretics increase the amount of urine passed, which causes the body to lose water and salt. Furosemide helps to treat high blood pressure (hypertension). It is not a cure. It also reduces the swelling and water retention caused by various medical conditions, such as heart, liver, or kidney disease. Generic furosemide tablets are available.

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the other one is:
METFORMIN (Glucophage® XR, Fortamet®, Glumetza™) is a medicine used to treat type 2 diabetes mellitus. Treatment is combined with a balanced diet and exercise. This medicine lowers blood sugar and helps your body to use insulin more efficiently. It is sometimes used with other medicines for diabetes. Generic metformin extended-release tablets are available.
Thank you for all your help.

I forgot to add that the yellow one has a triangle sort of on it. We really can't describe it but it's like a triangle that's not complete.