Drunken Builder

Apologies if this comes across as seeking legal advice, I'm not, I just want a general shove in the right direction!

A couple of months ago, my mother employed the services of a builder to do some work on the house. The work consisted of knocking through from the kitchen to the sitting room (which required putting in a steel supporting beam) and then revamping the bathroom; pulling out the old bath & suite, moving the position of the toilet and sink and installing a shower. A little bit of background info; the builder was doing some work in the house next door, this is how she came to employ him.

He started and completed the work downstairs with no bother, for which my mother paid him. He came back then to start on the bathroom, this is where the trouble started. He told my mam he would source and buy the shower tray and surround, and told her it was €500, which my mother gave him. He arrived back to the house with a tray and surround and set about pulling out the old bathroom.
A day or two into this work, myself and my mother were sitting downstairs when we saw his van leave at about 5.30pm. Thought nothing of it, but 20 mins later the neighbour knocked on the door, very irate, saying that he had knocked over the gate pillar between the houses, and accusing him of being drunk. The pillar was knocked over, but as I hadn't actually spoken to the builder that day I couldn't comment on whether or not he'd had a drink. I tried ringing him but there was no answer. He arrived back the next morning; we told him he'd knocked over the pillar and he said he hadn't noticed, apologised, and said he'd fix it. He spent the rest of the day working on the bathroom, moving pipes.
The next day, my mother left early. My sister arrived back to the house at lunchtime to find the builder absolutely legless. He couldn't stand or speak. She tried to get his van keys off him, but he wouldn't them go, got in the van and drove off. My sister called the guards to report him.

The following day he arrived back to the house, minus the van and with a big cut on his head. He begged to be given another chance, but my sister's husband told him no way, he couldn't be trusted and that he could collect his tools at a later date. He actually couldn't remember being at the house the previous day. We told him that we'd pay him for the work on the bathroom he'd already done, minus the cost of repairing the pillar and the cost of removing the skip (which he was supposed to have organised as part of the work downstairs)
He cleared off and we arranged another guy to finish the work (difficult to do a few weeks before xmas!)

Here's the clincher. First off, the skip was filled with rubble that wasn't from our house - he'd obviously dumped stuff from another job in it, so we had to pay for that and another mini skip to clear the mess from the work. Secondly, and more importantly, we discovered that the tray and shower he had supplied were at least 5 years old and were not the right size for each other. The shower was from B&Q, we phoned them and they told us that they hadn't made that shower in about 5/6 years, and that the size (850mm) was no longer made. He charged my mother €500 for it, when it was sold it was only €280 (and another €80 for the tray) We had to rip out the tray, refit another one and re-tile around it, as well as fork out for another shower cubicle. We reckon he had that shower in his shed for years and saw an opportunity to get rid of it at a healthy profit.

He phoned my sister's husband the other day enquiring if he could come up and collect his tools. My BIL, understandably told him that he was to first repay my mother the €500 she'd paid him for the shower. He refused point blank, claimed the shower was new, and denied being drunk, even though two of my sisters had seen him and spoken to him drunk and he'd admitted being drunk the day after he'd been in the house under the influence.

I'm absolutely furious, and really don't want him to get away with this shocking behaviour. While in was inconvenient having to try to quickly find another workman to finish the work, the thought that he has tried to fiddle my mother out of a substantial amount of money by trying to pass the shower off as a new one, followed by his adamant denial that he did that or was drunk is enraging. We are determined that he should at the very least pay for the cost of the skips, the repair to the pillar, and refund the cost of the shower (we still have it to return to him) The cost of the second workman (as well as the cost of re-doing the shower try and tiling) we're prepared to absorb. Where do I start with this? Small claims court, or elsewhere? Is it likely that we will recover any money from him? We still have his tools (we're not refusing to hand them back, he hung up the phone after the conversation with my sister's husband and hasn't been in contact since) My mother isn't really in a position to do anything about this as she suffers from extreme anxiety - she's been to the doctors since all this kicked off, is on sleeping tablets and is terrified he's going to knock on the door.