It might be a long shot but, I'm hoping that there's some central heating installers out there with records that back as far as 1974.
The reason is, I'm disposing of the first house I ever bought ( in
1974) and in working out the capital gain for tax purposes, I need to cost up the enhancements that I did to it. The most significant enhancement was a complete CH installation in 1974, with a gas CH boiler and 7 radiators . This was in a your average 3 bed semi with a ground and first floor. I seem to recall it might have been around =A31,200. Would this be about right?(( Out of interest, the previous owner used a single storage heater to warm the whole house. It was massive , ugly thing- about the size of a large chest deep freezer and sat in the lounge. It was supplied by off- peak electricity in the wee small hours, and gave up its heat during the day when the house was empty and I was out at work. Getting it out of the house was no small problem either. Glad I got shut of it :) ))