Apology for not having the ability to answer any of the logical questions and thanks for posting the pic Clemens. Interesting that the brake fluid reservoir is remote from the master cylinder, perhaps selected relative to maintaining the lowest possible bonnet line.

Another worthwhile question might be related to whether or not the ABS unit has a pump and if it`s ECU is built into the unit.

I did a bit of web wandering and was surprised to find a variety of faults related to Bosch ABS control units some where it affected speedometer read out, though found NO Bosch unit on the site below listed as being fitted to Morgan.

Bosch ABS Pumps & modules (ecutesting.com)

Seems the only mention of the brake rectification process carried out by the MMC has been related to a soft pedal and master cylinder replacement... No mention of MMC carrying out known work on any other part of the brake system..or have I picked that up wrong..?

Having noted the Litchfield comments...To further expand in the theme of modification for those interested in such pastimes and that Morgan might even have made use of something like this..? :-

ABS M5 Kit | Bosch Motorsport (bosch-motorsport.com)

A neighbour had two Nissan GTR`s from different eras, and told me he had planned to have the underside of the older one ice blasted and returned to look as new, the quote for all the work was reported as circa £10k with quite a few months to wait before they could take the car in.... Could all just be neighbourhood chat, though the cars were very real.