Service?
Er, what's that???
I run my cars on the basis of "if it ain't broke, don't fix it".
I keep the tyre pressures, oil and coolant topped up and I might get an oil change perhaps once every 5 years or so but otherwise, unless something goes wrong with it, my car never goes anywhere near to a garage.
I've been doing that for the past thirty years without any problems, so it's unlikely I'm going to change my habits any time soon.
On such an old car as you've got, I'd skip this year's service . . . and next year's . . . and the year after that . . . and . . .