Welcome N! I'm also new here and also an old fart of 48. I went the more expensive route and sold my MTB and purchased a hybrid which should be arriving tomorrow or Thursday. It's a BMC Alpenchallenge AC01. I'm also still, like you, overweight but I have been working hard at losing that weight. I started at 97kg and now weigh 83kg and I walk, on average, 7-10km per day. Make sure you throw up a pic of your frankenbike!