These are critical for even cooling, the flaps not only provide for
quick warm up, they direct the flow to the right places, and hot spots
can develop without them.  You might be able to get away without the
thermostat and fix the flaps open in your climate, but you are probably
better off using it.  I would start calling the yards for an intact set
of flaps if I were you.
--
Stuart MacMillan
Seattle

'84 Vanagon Westfalia w/2.1
'65 MGB (Daily driver since 1969)
'74 MGB GT (Restoring sloooowly)

Assisting on Restoration (and spending OPM):
'72 MGB GT (Daughter's)
'64 MGB (Son's)

Stripped and gone but their parts live on:
'68 MGB, '73 MGB, '67 MGB GT