They are probably just the brackets that came with the tripod and are
screwed or laged into the roof sheething. When your tar and gravel roof
was installed they just gooped over everything to seal it up. The lead
wire enty point may have been done through an upside down 4" handy box.
You have a few options.
1) If its not leaking, just abandon it and install a new antenna. Use
sandbags to secure it so you do not need to penetrate the roof.
2) if it is leaking, remove everything down to the sheathing. Roof
cement then spread out the gravel. Use the sandbag trick.
3) Remove everything, install new tripod brackets, roof cement, replace
4) Remove everything, repair roof with roofing cement, replace gravel.
Install a new antenna on side of house with stand off brackets lagged
into side of house.
5) Remove everything, repair roof with roofing cement, replace gravel.
Install a new antenna on to chimney with wrap around bands or masonary
If it were me, I would do option #5. You get the asthetic benefit of
having a less visible antenna AND you no longer have a potential for a
leak. Find a new route for your new antenna wire that does not
interfeer with the roof. it may mean more wire but thats cheaper than
damage caused by a leak. it looks like you have a very small attic. Run
the cable from the chimney to the closest gable end and enter there and
then follow the path of the old wire if need be. Also, your new wire
will likely be 75OHM coax, not 300 Ohm flat wire like it looks you old
antenna used. Good luck if shopping at radio shack. They may have
everything you need but you will likely have an idiot helping you. I
have heard good things about http://www.antennaweb.org/aw/welcome.aspx
for selection help. I do not know a good brand or place online to buy