I don’t think that’s the original pump but it might be worth doing a rough pressure test on it to see how well it’s doing. Then you’ll know if to carry a spare or not. The older the pump, the better it is it would seem and that looks old but not the original. I’ve had a modern replacement last less than a week, and I’ve had its replacement last four plus years. To do a check on the old one, pop the fuel pipe off from the carb and shove it in an empty 1.5 - 2L water bottle on its side , slide it in about an inch or so and get your assistant to crank the engine and count to three then stop. The fuel coming out of the pipe should hit the bottom of the bottle with a little gusto in top condition and on the other hand just a limp drip just inside the neck if it’s almost buggered. Disable your engine from starting first, and don’t set yourself on fire by doing it on a hot engine. There’s lot that can go wrong here so be careful and hold the bottle and the pipe and mind the fan belt. The other issue is, can you get it off easily as it’s fitted on a block / guide that’s easy to break and the other thing to check is that the pushrod is still long enough as that wears down too. Will it clear the dynamo for removal ???. When you have it apart, it may be worth checking your fuel, pipes and clips , if they’re old, they may not take kindly to being removed and shoved back on again. That jubilee clip looks a bit tooooo big, might have got away with it so far but might not once the pipe is removed and replaced.
Do the pressure test then have a ponder once you know.
Ozziedog,,,,,,, it’s never straight forward is it.