Give Phil At Road&Race a call https://www.rrtransmissions.com/ he sure can help you. BTW i don't think there is a visual difference or any difference between an Ital and a 1.8ltr Marina axle.
It is important with a 6V system that your cables are thick enough, thicker than a 12V system. Equally important is to run the main negative earth direct to the starter motor to avoid current losses. Used to service the odd Jeep and Minerva derivative in military service and never had problems cranking, even a 1947 EMW i did some work on had no problem with cranking on 6V. If i remember correct a coil with resistor is a 9V coil but is powered by 12V but only while cranking.
I use Longacre scales, as proper corner weight scales they are fit for purpose. At race car direct you can find them sometimes sec.hand. The cheapest new one's are about 1K.
You can also use a Clio expansion bottle https://www.ebay.co.uk/itm/Renault-Clio-Mk2-1-5-dCi-2-0-16v-Sport-Radiator-Expansion-Tank-Bottle-Cap/163231324908?fits=Car+Make%3ARenault%7CModel%3AClio&
Something like this maybe ? https://www.ebay.co.uk/itm/Universal-Exhaust-4-x-2-x-20-Silencer-Kit-Car-Resonator-Muffler-Back-Box-304/323472103515?hash=item4b5070985b:g:8WUAAOSwMVdYGwqN
Due to a change of plans i have a complete big brake set, disc's,calipers,new pads and flexible hoses. the disc's have been resurfaced so virtually new. 400 GBp for the lot and 30 GBp P&P, pic to follow
i want to operate a wipermotor with a on/off/on toggle switch and want to use a 5 pin relay for it so if i connect the toggle switch slow speed to 86 and 87 of the relay and 30 to the wiper motor slow speed and position 2 on the wiper connector to 87A would that work ? I could answer my own question but that would be like lipstick on a pig would it ?
The vibration the brakes produce should be addressed but the sound seems to come from the scuttle area, could it be something that is slightly loose that is fixed on the scuttle ?
If his chassis is short cockpit it would have this pedal arrangement. I don't know what year the short cockpit was faced out of production maybe 1996 ?