I am using Leak TL12.1 amps that are over 50 years old!
I have changed all signal caps to Mundorf silver-gold with great results, I am using the original Paper in Oil Can cap for the power supply, they are a bit low but sound wonderfull, I was instructed by a lot of "experts" not to touch them! If you are using your amps daily they should be fine, Try to get them measured before sending them off to get fixed!
I would say you will eventually need to change them so just decide which is the best time to do it! If you change them yourself or some technician close to you, you can decide which caps to use...these make a huge diference in sound, Do you want Blackgates, Elna cerafine for the Power supply? Do you want the original (20 year old design) caps for the signal path, will you just let HK put whatever they can get cheap! Do you want to try the latest in caps that add great resolution to your amp like the Mundorf Silver-oil or Silver gold, or the Teflon Vcaps, do you want a softer sound like paper in oil caps? Do you want a more crisp sound like Hovland caps? Are you confused enough already? This is a great hobbie go for it change them and play with the sound you like!!