Manifold Pressure/Fuel Pressure Gauge

[ADIRU]

Our MX7-180 (O360-C1-F) needs a new or overhauled combined MP/Fuel Pressure gauge. Unfortunately due to current lockdown restrictions we are unable to travel to our aircraft to check the OEL and identify the model installed on our machine.
We know that it will be one of the following four:
Aerosonic 735-102, EDO-Aire/Sigma Tek IU028-005-38, Castleberry Instruments & Avionics 6331 H 14 or United Instruments UI6333-H.170.
I have tried searching (at length) on Google but without success and hoped that some kind soul might be able to help.
Here's an image (hopefully)

https://www.flickr.com/photos/187986710 ... ed-public/

Thank you all
If the image fails to show, the gauge has MP on the left side (10-35 with green from 15-29) and Fuel Pressure on the right from 0-10.5 (green from 0.5-8 )
P.S. Posting from the UK

[maules.com]

In your POH are The Required equipment and Optional equipment lists.
I the Instruments pages should be the instruments mounted in that airplane. One of the choices will have a stamp or check mark. If it has been changed before it should show a change. Or look through your airframe logbook and any change should be listed there and a service tag might be in your paperwork.

[ADIRU]

Thank you very much for taking the time to reply Jeremy.
With due respect, I'm already aware of the OEL and quoted the four items from there. As I mentioned, we in the UK are unable to travel due to lockdown restrictions and so I am unable to access our aeroplane's actual copy of the OEL and hence my original posting.
We are not in possession of our airframe logbook either as this is held by the maintenance organisation that looks after our Maule and they are currently shut due to Covid 19.