bill,intresting to hear you have a buma portable borer l worked for them for about 20yrs off and on good little machine although l would say that as l milled all the parts they were first made with power stations in mind we done alot of breakdown parts for them obviously when a power station is having a problem with a part they dont want to stop production of electricity so to avoid stripping down lengthy and expensive procedure they bored part out where it was sleeved it finished bored it only replacing part when it was unsalvagable that mean they could plan a big strip down and have alternate backup whilst replacing it a lot of them went overseas it was only a small outfit but had a good reputation-happy days look after it will be rare in a few yrs time