Trakhak

Yes, Viscount bikes (also marketed as Lambert bikes) were decent, with a couple of caveats.

The bikes were originally equipped with an aluminum fork that used a failure-prone design for attaching the steerer tube to the fork crown. If your bike's fork is aluminum, it should definitely be replaced. (Yamaha Corporation bought the rights to Viscount bikes some time in the 1970s and assumed responsibility for replacing the defective forks, so if your fork is aluminum, check with Yamaha for a replacement.)

The company that manufactured the Lambert/Viscount bikes produced many of the bike's components as well, including the brakes, hubs, derailleurs, pedals, and crankset.

I can't remember all the details, since it's been a long time since I working in a shop that sold Lamberts, but I think that the hubs might have used sealed industrial bearings instead of the cup-and-cone bearings used by all other hub manufacturers at the time.

Most of the other proprietary components were of decent but not great quality, with the exception of the crankset, which used a peculiar nontapered crank/spindle interface that relied on a splined washer to hold the crank in place. Not a great design. The workaround for installing a crankset with a standard crank/spindle interface was to pull the (sealed) bearings from the bottom bracket and cut new threads in the bottom bracket shell (36 x 24 Italian threading worked, I believe).

All that said, the frame seems to have been durable enough and is very light. I remember how thrilled we were to be able to sell a 21-pound Lambert at a price about 25% lower than that of other bikes of comparable weight.