Hello GB&C

I recently bought a an amp over ebay. I was assured it had been serviced recently and that it was all working but when I turn it on, it seems so dull. After leaving it on standby for about 5 minutes, the tubes are barely glowing, and most can be touched by hand without burning (but they do feel warm). Are the tubes blown in it or it something worse?

Can you send it back? You do not want to get into troubleshooting a Silvertone. You'd be lucky indeed if the tubes were the only thing wrong with it.
I'm sort of at loggerheads with him at the moment through e-mails. He says it was sent in a working condition, and to me, while it's "working" it's not working as it should. He also told me that if i could prove it wasn't working by having it assessed by a technician, he might consider a refund. But quite frankly, i'd rather not have to scour for a tech who can do this, then pay more money for it.
Well, in that case a new set of tubes is your only option. If you're lucky they will fix the problem. If not, you are going to have to take it to a tech. There's not much more we can diagnose over the internet, and even less we can help you fix.

It needs to go to a tech anyway, to check the filter caps and power supply. These old amps almost always require maintenance to make them anywhere near reliable, so while it "works" in that it makes sound, it's very unlikely that it doesn't need some repairs internally.

This is why we were trying to steer you away from the Silvertone in your earlier thread. They're old amps that were not very well built, so you have to expect issues when you buy one. Hopefully it's just a blown tube for now, but you do need to take it to a tech to see what's up. If it still has the original filter caps and one of them goes bad it may kill the amp permanently.
I have opened a case because frankly, i've been frauded here. I know it was advised against me, but the alternatives suggested didn't fit the bill for me, and i managed to get hold of it for a lower price.