hard to verify
But, as long as it sounds great, enjoy it. Could be from Garage who knows?
About recapping, Black Gates will not sound as warm as the frako caps you replace.
Speak to a competent person who knows what high quality caps will maintain that type of warm, oomphy, clear, yet velvety sonic character.
The dark brown AB carbon composition resistors on the board also contribute to the sound, as well as the the pots, transistors, and circuit design.
Resistors DO NOT go bad, they work or they don';t, so DO NOT replacer dark brown resistors UNLESS you must.
Im thinking you might look into 2 or 4 Paper In Oil caps for the spot in circuit, for that certain tone. Vintage Siemans, or Sprague.
Call a parts house, like hndme.com, ask questions, tell what you have, pester them, then after education and research, make purchases and be happy. Also google will turn up lots of boutique parts places.
PM me, Ill tell u which places are good which arent. Example, stay away from welbornelabs,.com
Mr. Scott Fitlin