I went up into the loft last night in search of my Grange kit. I’m afraid that it is not the M&L kit which I have. It is one produced by Westward. It also doesn’t have a Perseverance chassis with it.
I would strongly echo Stuart’s suggestion of Iain Rice’s book on chassis building as an excellent place to start. Whilst some new ideas and products have emerged in the decades since it was written – notably the use of Continuous Spring Beams (CSB) for locomotive suspension – there is probably no better primer on how to build a successfully working chassis.
I would differ from Stuart’s advice in one respect though. In my view, the absolute best hornblocks to use for any suspension purpose are those from High Level Kits. Not only are the components beautifully etched and machined, they are assembled with no solder at all, until you come to fix them in the chassis. They also have lovely little useful touches designed in, such as holes for keep-wires to stop the bearing dropping out, and a tab to ensure it is fixed at the correct height in a frame (assuming that the hornblock cut-outs are in the right place to start with!). And you would not find a more helpful person than Chris at High Level to ensure that you have the right item and it worked well.