Thanks for the info guys!
It does feel very light in weight and he used it for bird and rabbit. He did his own reloads and I have 2 boxes of his shells - they are 2 3/4.
There is a piece missing from the bottom edge of the stock, but I don't think it was ever repaired...
I do have more questions about this gun as I know very little about it and would like to learn more...
1. How do you determine the date? Is it through the serial number?
Date code is stamped on the flat along with the other proof marks - XXIII = 1967 Please refer to the following site: http://www.shotgunworld.com/bbs/viewtopic.php?f=57&t=73492
2. were these also referred to as BL series guns and silver snipes?
No, different models
3. How do you tell what the chokes are? Is it the stars stamped on the barrel? Top barrel has 1 star - Full, bottom barrel has 3 stars - Mod?
True. That was/may still be the original constriction. [/B]
4. On the bottom barrel, to the right side of the 3 stars there is a number 3 stamped, is this the chamber size?
Unable to see clearly. But no, chamber length should be stamped someplace - example: 70 (i.e. = 2 3/4inch) .....
5. which trigger fires which barrel?
In the case of O/U shotgun with DTs, front trigger for bottom bbl
6. I don't think he would have ever had the chokes opened up...is there a way to tell or an obvious sign?
Only way to determine actual constriction is via a choke gauge ..... even factory defaults may somewhat vary when measured despite what is stamped on the barrels.
7. I realize that parts may be hard to find but I'm guessing that these were well built. However, are there certain parts that do tend to wear? firing pins, barrel locking pins etc?
Any mechanism is prone to wear. Major causes of premature wear is usually abuse, maintenance neglect. You may wish to have the shotgun inspected by a knowledgeable person or a competent gunsmith.
8. Any source for an online manual? I went to a Beretta website and while they didn't have a specific manual for the model, there was a general one for their O/U guns...
Suggest check "ShotgunWorld" forum. Generally speaking, the handling/maintenance procedure will not vary much from current production guns.
9. Lead shot only through the barrel?
Yes, and light loads (read 1oz) considering the weight. Condition of the wood (stockhead etc) will need to be considered as well (ensure no hairline cracks etc.) Non-tox shells such as Kent Tungsten Matrix will work fine but those equate to higher $. 
10. What areas do you oil? I'm guessing for sure the hinge area....
Plenty of videos on YouTube. Suggest MidwayUSA clips by Larry Potter. After cleaning, lightly smear good grease on the friction points/hinge areas example: where barrel mates with the receiver/forend etc. Use light coat of oil or G96 for the rest of metal parts/barrel/bore etc. Do not allow oil to seep into the wood, stockhead etc.
Aside from some dings and scuffs in the wood and some blemishes on the barrel - mainly under the wood forend, the gun looks pretty solid. I will have a closer look down the barrels with a light.
I know its a matter of personal preference in terms of keeping the gun as is or, having it refinished, but would there be any point in having this done? re-bluing the barrels, re-staining the stock etc...This gun has sentimental value so I will be keeping it and using it!
I'm afraid end-to-end refinish via a good smith will cost quite a bit.