Advice on buying vintage Rolex Date

[photodawg]

I am entertaining the possibility of buying a vintage Rolex Date ref. 1550 with a gold case (not solid), acrylic crystal and the fluted bezel, I guess you would call it fluted, it isn't smooth, and a blue dial, no bracelet.
I have seen photos of it, and the owner said it was his grandfathers, and was looking to sell it, and I asked him to find the reference number and the serial number. He found the reference #1550, but he said the serial number has been filed off, and he said not worn because it had an after market band, but filed.
My question is does this affect the value and does will it cause problems with getting service and somebody raising concerns about if it is "hot" or not, and is there a serial number inside the case?
Not really sure about the value, but I would say from the photos the watch appears in fair condition.
Thanks for any help in this matter.

[Tools]

There is absolutely no reason in the world to file off a serial number unless there is something to be hidden by that action..........

If you send it to Rolex, they may be able to chemically retrieve the number or identify it by the number on the movement....

There are many older watches where the numbers on the side have been degraded by the movement of the end-links against the case side, so I suppose it would need to be looked at to determine if it was actually filed..

Most scams usually start with "This belonged to my father/grandfather, and I really don't know anything about it."