Boy that radio brings back memories. I forgot I owned one back when. Looked it up on the net. Vintage late 1960's-1970's. I would suggest you try something simple first. Get a can of tuner cleaner and clean the bandswitch; don't over spray. Probably wouldn't hurt to spray the volume control and front panel controls. HTH.
The capacitor that I thought was the problem was not.
There is one that is in front of the suspected one, in the cold the AM didn't work, brought it outside and the AM BC band would work, thermal...
So I took a chance and it now works.
That was the Allied Model, actually there are 2 Ceramic Capacitors 8pf and then on the opposit side of the board there is a 5pf, so I replaced the 8 and resoldered the 5pf back to where it was originally.
Then it got me thinking about the Aircastle, so for a preventive maint I replaced that one as well BUT it had a 15pf on it, I replaced it with a 8pf, it is alot more sensitive now, a hell of alot more.
Like I stated in a previous post, I do not like any of my shortwave radios past and present, to run on AC, so I desoldered the power supply from both units all the wires are desoldered from the mb and the power supply itself had 2 nuts holding it everything was removed batteries are more stable regulated 6V.
The batteries in these units seem like they are going to last a long time, i'd say over 100 hrs...