There are still plenty of these boilers about. If it contains asbestos, there should be a warning sticker on the boiler indicating its use. Its use on the boiler would otherwise be be common knowledge throughout the gas appliance repair community.
Some of the seals /gaskets are made of Kaowool, another man made fibre, which is not asbestos. It can cause irration of the skin if handled.
I suggest you seek out another Gassafe registerred gas fitter to inspect and service your boiler.
Philip, February 2010