The best answer to the problem I think, is to convert back o the original Issigonis design Mini Central Speedo type dash, as many later Mini owners do including me. The original parts required are all available new (or a lot cheaper secondhand at Mini Shows/Autojumbles or on Ebay, etc.)
Alternatively 'Hawthorn Mini Works' and others do aftermarket versions which incorporate space for a rev counter, etc.
Minispares - CENTRE CLOCK CONVERSION - WIRING HARNESS:-
"This is the wiring short conversion loom that fits to the old central speedo and is used by people modifying from 2 or 3 clock dashes to single clock or just repairing damaged looms. With the correct bulb holders and spade fittings. Now uses 5x GLB987 and 2X GLB2132 bulbs."
https://www.minispar...-wiring-harness
HMW Performance Dash Binnacle £175.00
"The HMW Performance Dash is a bolt-in centre binnacle for the Classic Mini - allowing you to mount the Speedo, an 80mm Rev Counter, and THREE 52mm ancillary gauges, all whilst sticking with the iconic look of the centre binnacle! The speedo mounts directly to the binnacle - no need for additional brackets or housings!"
https://www.hawthorn...e-dash-binnacle
Nippy Cars Mini Dash Binnacles:-
https://nippycarsonl...-category/dash/
COOPER S 3 CLOCK BINNACLE SET 130MPH (Minispares) :-
"Complete binnacle set for centre speedo cars, kit includes 130 mph black speedo, temperature gauge, oil pressure gauge, binnacle and chrome surround (incl clips). Mini Spares also have a short loom which converts 3 clock Nippon Seiko gauge clusters positioned in front of driver to convert over to this 3 clock central fitting kit. Order as PM05."
https://www.minispar...acle-set-130mph
TMF Frequently Asked Questions - Converting To A Centre Speedo:-
https://www.theminif...-centre-speedo/
Edited by mab01uk, Yesterday, 10:40 AM.