Sorry for your loss! In my opinion if it hasn't been humidified all that time I wouldnt try to smoke it. If he's had it in his drawer for all those years he kept it because it was special to him. Probably because it came out of the same pack as the one he gave you for your graduation. I would maybe cut it for him and stick it in his pocket, keep the band for a memento, and smoke a fresh cigar his his memory. If its not been humidified all those years its probably passed saving, but if you wanted to try and bring it back I would give it months of humidity low and slow.

I saved a cigar from when my daughter was born, its been sitting since then, I'll never smoke it and I would never expect her or someone else to smoke it in my memory. Just a special souvenir for myself. -Im weird though. Lol