Service Meter Sight Glass Part#

I have an early 1950 D4 7U, however the engine has been replaced with a later model 4 cylinder CAT engine. I'm told the later engine has a balancer and direct electric start head--otherwise it looks like the old engine. The service meter lens is opaque so I can't read the hours. I've recently rebuilt the engine and wish to track it's use. Unlike ordinary 7U and 9U service meter lenses this one is retangular and exposted [uncovered]. Four screws secure it to the meter's housing. I can't find this meter or cover in any of my Cat D4 tractor or engine parts books. The Cat's not with me at the moment so I can't provide a meter housing part number. Can anyone tell me the part number for the lens, or a kit which includes, lens, gasket and screws.

Hi Roverman,

gasket 5A5764 - 1
window 5A5765 - 1
screw 5A5766 - 4
washer 5A5767 - 4

Cheers,
Eddie B.