Mark Hello,
I purchased a padded dash replacement from one of the 'big houses' you mentioned. It is beautiful! However, the padded part on the left instrument side is of some concern. The padding, which is a liquid type of hardened foam, makes the distance between the surface black vinyl and the metal dash much thicker than the original design. Consequently, the gauges, lights, heater knob, etc. are approx 5mm to approx 8 mm above the steel fascia. For the gauges it dosnt matter, the rear adjusting pieces allow for variance. Conversely, I've seen where people cut the opening wide, and bury the gauge into the foam, leaving the chrome ring below the black vinyl. My heater control knob on the far left wouldnt fit to screw in at all! As I didnt want to cut out the foam and bury the knob in the foam, I left it blank, and will relocate the heater control knob elsewhere, or leave it out entirely.....havnt decided yet. The choke knob and dimmer control knob fit and secure well. I used 3M Trim adhesive spray to glue the vinyl edges to the back of the steel dash fascia, and a light touch with a heat gun to help shape the vinyl. That part went well. If you check out Classic Motorsports magazine, they did a great series rebuilding a 'Modern' Midget with Carl Heideman of Eclectic Motorworks. There are (or used to be), a couple of photos of their replacement dash work, though its difficult to tell if they had similar concerns. I did a MGB several years ago and it was the same situation with the replacement dash piece, (one I bought from Moss, the other from VB, probably the same supplier).
The dash replacements look very good, maybe even better (?). They last well with normal use. As mentioned I use 3M Trim Adhesive from Amazon.com, and its great.
If you want, click on my photo link, then click on 'Minors Gallery', then click on '1974 MGB', and you can see an example of a replacement dash placed about 10 years ago.....its the same as the Midget in materials and quality.
I'll try to photograph the Midget dash tonight and put it on the Midget photoalbum for you to look at front and back.